Update Go version to 1.23

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alex@openfaas.com>

gateway/vendor/github.com/prometheus/common/expfmt/encode.go

@@ -68,7 +68,7 @@ func Negotiate(h http.Header) Format {
 		if escapeParam := ac.Params[model.EscapingKey]; escapeParam != "" {
 			switch Format(escapeParam) {
 			case model.AllowUTF8, model.EscapeUnderscores, model.EscapeDots, model.EscapeValues:
-				escapingScheme = Format(fmt.Sprintf("; escaping=%s", escapeParam))
+				escapingScheme = Format("; escaping=" + escapeParam)
 			default:
 				// If the escaping parameter is unknown, ignore it.
 			}
@@ -101,7 +101,7 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 		if escapeParam := ac.Params[model.EscapingKey]; escapeParam != "" {
 			switch Format(escapeParam) {
 			case model.AllowUTF8, model.EscapeUnderscores, model.EscapeDots, model.EscapeValues:
-				escapingScheme = Format(fmt.Sprintf("; escaping=%s", escapeParam))
+				escapingScheme = Format("; escaping=" + escapeParam)
 			default:
 				// If the escaping parameter is unknown, ignore it.
 			}

gateway/vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -15,7 +15,7 @@
 package expfmt
 
 import (
-	"fmt"
+	"errors"
 	"strings"
 
 	"github.com/prometheus/common/model"
@@ -109,7 +109,7 @@ func NewOpenMetricsFormat(version string) (Format, error) {
 	if version == OpenMetricsVersion_1_0_0 {
 		return FmtOpenMetrics_1_0_0, nil
 	}
-	return FmtUnknown, fmt.Errorf("unknown open metrics version string")
+	return FmtUnknown, errors.New("unknown open metrics version string")
 }
 
 // WithEscapingScheme returns a copy of Format with the specified escaping

gateway/vendor/github.com/prometheus/common/expfmt/openmetrics_create.go

@@ -152,8 +152,8 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily, options ...E
 	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(compliantName, "_total") {
 		compliantName = name[:len(name)-6]
 	}
-	if toOM.withUnit && in.Unit != nil && !strings.HasSuffix(compliantName, fmt.Sprintf("_%s", *in.Unit)) {
-		compliantName = compliantName + fmt.Sprintf("_%s", *in.Unit)
+	if toOM.withUnit && in.Unit != nil && !strings.HasSuffix(compliantName, "_"+*in.Unit) {
+		compliantName = compliantName + "_" + *in.Unit
 	}
 
 	// Comments, first HELP, then TYPE.

gateway/vendor/github.com/prometheus/common/expfmt/text_parse.go

@@ -895,7 +895,7 @@ func histogramMetricName(name string) string {
 
 func parseFloat(s string) (float64, error) {
 	if strings.ContainsAny(s, "pP_") {
-		return 0, fmt.Errorf("unsupported character in float")
+		return 0, errors.New("unsupported character in float")
 	}
 	return strconv.ParseFloat(s, 64)
 }

gateway/vendor/github.com/prometheus/common/model/alert.go

@@ -14,6 +14,7 @@
 package model
 
 import (
+	"errors"
 	"fmt"
 	"time"
 )
@@ -89,16 +90,16 @@ func (a *Alert) StatusAt(ts time.Time) AlertStatus {
 // Validate checks whether the alert data is inconsistent.
 func (a *Alert) Validate() error {
 	if a.StartsAt.IsZero() {
-		return fmt.Errorf("start time missing")
+		return errors.New("start time missing")
 	}
 	if !a.EndsAt.IsZero() && a.EndsAt.Before(a.StartsAt) {
-		return fmt.Errorf("start time must be before end time")
+		return errors.New("start time must be before end time")
 	}
 	if err := a.Labels.Validate(); err != nil {
 		return fmt.Errorf("invalid label set: %w", err)
 	}
 	if len(a.Labels) == 0 {
-		return fmt.Errorf("at least one label pair required")
+		return errors.New("at least one label pair required")
 	}
 	if err := a.Annotations.Validate(); err != nil {
 		return fmt.Errorf("invalid annotations: %w", err)

gateway/vendor/github.com/prometheus/common/model/metric.go

@@ -14,9 +14,11 @@
 package model
 
 import (
+	"errors"
 	"fmt"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
 	"unicode/utf8"
 
@@ -269,10 +271,6 @@ func metricNeedsEscaping(m *dto.Metric) bool {
 	return false
 }
 
-const (
-	lowerhex = "0123456789abcdef"
-)
-
 // EscapeName escapes the incoming name according to the provided escaping
 // scheme. Depending on the rules of escaping, this may cause no change in the
 // string that is returned. (Especially NoEscaping, which by definition is a
@@ -307,7 +305,7 @@ func EscapeName(name string, scheme EscapingScheme) string {
 			} else if isValidLegacyRune(b, i) {
 				escaped.WriteRune(b)
 			} else {
-				escaped.WriteRune('_')
+				escaped.WriteString("__")
 			}
 		}
 		return escaped.String()
@@ -317,21 +315,15 @@ func EscapeName(name string, scheme EscapingScheme) string {
 		}
 		escaped.WriteString("U__")
 		for i, b := range name {
-			if isValidLegacyRune(b, i) {
+			if b == '_' {
+				escaped.WriteString("__")
+			} else if isValidLegacyRune(b, i) {
 				escaped.WriteRune(b)
 			} else if !utf8.ValidRune(b) {
 				escaped.WriteString("_FFFD_")
-			} else if b < 0x100 {
+			} else {
 				escaped.WriteRune('_')
-				for s := 4; s >= 0; s -= 4 {
-					escaped.WriteByte(lowerhex[b>>uint(s)&0xF])
-				}
-				escaped.WriteRune('_')
-			} else if b < 0x10000 {
-				escaped.WriteRune('_')
-				for s := 12; s >= 0; s -= 4 {
-					escaped.WriteByte(lowerhex[b>>uint(s)&0xF])
-				}
+				escaped.WriteString(strconv.FormatInt(int64(b), 16))
 				escaped.WriteRune('_')
 			}
 		}
@@ -389,8 +381,9 @@ func UnescapeName(name string, scheme EscapingScheme) string {
 			// We think we are in a UTF-8 code, process it.
 			var utf8Val uint
 			for j := 0; i < len(escapedName); j++ {
-				// This is too many characters for a utf8 value.
-				if j > 4 {
+				// This is too many characters for a utf8 value based on the MaxRune
+				// value of '\U0010FFFF'.
+				if j >= 6 {
 					return name
 				}
 				// Found a closing underscore, convert to a rune, check validity, and append.
@@ -443,7 +436,7 @@ func (e EscapingScheme) String() string {
 
 func ToEscapingScheme(s string) (EscapingScheme, error) {
 	if s == "" {
-		return NoEscaping, fmt.Errorf("got empty string instead of escaping scheme")
+		return NoEscaping, errors.New("got empty string instead of escaping scheme")
 	}
 	switch s {
 	case AllowUTF8:

gateway/vendor/github.com/prometheus/common/model/silence.go

@@ -15,6 +15,7 @@ package model
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"regexp"
 	"time"
@@ -34,7 +35,7 @@ func (m *Matcher) UnmarshalJSON(b []byte) error {
 	}
 
 	if len(m.Name) == 0 {
-		return fmt.Errorf("label name in matcher must not be empty")
+		return errors.New("label name in matcher must not be empty")
 	}
 	if m.IsRegex {
 		if _, err := regexp.Compile(m.Value); err != nil {
@@ -77,7 +78,7 @@ type Silence struct {
 // Validate returns true iff all fields of the silence have valid values.
 func (s *Silence) Validate() error {
 	if len(s.Matchers) == 0 {
-		return fmt.Errorf("at least one matcher required")
+		return errors.New("at least one matcher required")
 	}
 	for _, m := range s.Matchers {
 		if err := m.Validate(); err != nil {
@@ -85,22 +86,22 @@ func (s *Silence) Validate() error {
 		}
 	}
 	if s.StartsAt.IsZero() {
-		return fmt.Errorf("start time missing")
+		return errors.New("start time missing")
 	}
 	if s.EndsAt.IsZero() {
-		return fmt.Errorf("end time missing")
+		return errors.New("end time missing")
 	}
 	if s.EndsAt.Before(s.StartsAt) {
-		return fmt.Errorf("start time must be before end time")
+		return errors.New("start time must be before end time")
 	}
 	if s.CreatedBy == "" {
-		return fmt.Errorf("creator information missing")
+		return errors.New("creator information missing")
 	}
 	if s.Comment == "" {
-		return fmt.Errorf("comment missing")
+		return errors.New("comment missing")
 	}
 	if s.CreatedAt.IsZero() {
-		return fmt.Errorf("creation timestamp missing")
+		return errors.New("creation timestamp missing")
 	}
 	return nil
 }

gateway/vendor/github.com/prometheus/common/model/value_float.go

@@ -15,6 +15,7 @@ package model
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math"
 	"strconv"
@@ -39,7 +40,7 @@ func (v SampleValue) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements json.Unmarshaler.
 func (v *SampleValue) UnmarshalJSON(b []byte) error {
 	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
-		return fmt.Errorf("sample value must be a quoted string")
+		return errors.New("sample value must be a quoted string")
 	}
 	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
 	if err != nil {

gateway/vendor/github.com/prometheus/common/model/value_histogram.go

@@ -15,6 +15,7 @@ package model
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -32,7 +33,7 @@ func (v FloatString) MarshalJSON() ([]byte, error) {
 
 func (v *FloatString) UnmarshalJSON(b []byte) error {
 	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
-		return fmt.Errorf("float value must be a quoted string")
+		return errors.New("float value must be a quoted string")
 	}
 	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
 	if err != nil {
@@ -141,7 +142,7 @@ type SampleHistogramPair struct {
 
 func (s SampleHistogramPair) MarshalJSON() ([]byte, error) {
 	if s.Histogram == nil {
-		return nil, fmt.Errorf("histogram is nil")
+		return nil, errors.New("histogram is nil")
 	}
 	t, err := json.Marshal(s.Timestamp)
 	if err != nil {
@@ -164,7 +165,7 @@ func (s *SampleHistogramPair) UnmarshalJSON(buf []byte) error {
 		return fmt.Errorf("wrong number of fields: %d != %d", gotLen, wantLen)
 	}
 	if s.Histogram == nil {
-		return fmt.Errorf("histogram is null")
+		return errors.New("histogram is null")
 	}
 	return nil
 }