Migrate to containerd v1.7.0 and update dependencies

* Updates containerd to v1.7.0 and new binary for 32-bit
Arm OSes.
* Updates Go dependencies - openfaas and external

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

vendor/github.com/imdario/mergo/merge.go

@@ -38,10 +38,10 @@ func isExportedComponent(field *reflect.StructField) bool {
 }
 
 type Config struct {
+	Transformers                 Transformers
 	Overwrite                    bool
 	AppendSlice                  bool
 	TypeCheck                    bool
-	Transformers                 Transformers
 	overwriteWithEmptyValue      bool
 	overwriteSliceWithEmptyValue bool
 	sliceDeepCopy                bool
@@ -76,10 +76,10 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 			}
 		}
 		// Remember, remember...
-		visited[h] = &visit{addr, typ, seen}
+		visited[h] = &visit{typ, seen, addr}
 	}
 
-	if config.Transformers != nil && !isEmptyValue(dst) {
+	if config.Transformers != nil && !isReflectNil(dst) && dst.IsValid() {
 		if fn := config.Transformers.Transformer(dst.Type()); fn != nil {
 			err = fn(dst, src)
 			return
@@ -205,6 +205,16 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 				dst.SetMapIndex(key, srcElement)
 			}
 		}
+
+		// Ensure that all keys in dst are deleted if they are not in src.
+		if overwriteWithEmptySrc {
+			for _, key := range dst.MapKeys() {
+				srcElement := src.MapIndex(key)
+				if !srcElement.IsValid() {
+					dst.SetMapIndex(key, reflect.Value{})
+				}
+			}
+		}
 	case reflect.Slice:
 		if !dst.CanSet() {
 			break