Bump google.golang.org/protobuf from 1.31.0 to 1.33.0

Bumps google.golang.org/protobuf from 1.31.0 to 1.33.0.

---
updated-dependencies:
- dependency-name: google.golang.org/protobuf
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/protobuf/internal/impl/codec_extension.go

@@ -21,26 +21,18 @@ type extensionFieldInfo struct {
 	validation          validationInfo
 }
 
-var legacyExtensionFieldInfoCache sync.Map // map[protoreflect.ExtensionType]*extensionFieldInfo
-
 func getExtensionFieldInfo(xt protoreflect.ExtensionType) *extensionFieldInfo {
 	if xi, ok := xt.(*ExtensionInfo); ok {
 		xi.lazyInit()
 		return xi.info
 	}
-	return legacyLoadExtensionFieldInfo(xt)
-}
-
-// legacyLoadExtensionFieldInfo dynamically loads a *ExtensionInfo for xt.
-func legacyLoadExtensionFieldInfo(xt protoreflect.ExtensionType) *extensionFieldInfo {
-	if xi, ok := legacyExtensionFieldInfoCache.Load(xt); ok {
-		return xi.(*extensionFieldInfo)
-	}
-	e := makeExtensionFieldInfo(xt.TypeDescriptor())
-	if e, ok := legacyMessageTypeCache.LoadOrStore(xt, e); ok {
-		return e.(*extensionFieldInfo)
-	}
-	return e
+	// Ideally we'd cache the resulting *extensionFieldInfo so we don't have to
+	// recompute this metadata repeatedly. But without support for something like
+	// weak references, such a cache would pin temporary values (like dynamic
+	// extension types, constructed for the duration of a user request) to the
+	// heap forever, causing memory usage of the cache to grow unbounded.
+	// See discussion in https://github.com/golang/protobuf/issues/1521.
+	return makeExtensionFieldInfo(xt.TypeDescriptor())
 }
 
 func makeExtensionFieldInfo(xd protoreflect.ExtensionDescriptor) *extensionFieldInfo {