Update module github.com/prometheus/client_model to v0.6.1

vendor/github.com/golang/protobuf/proto/registry.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"sync"
 
+	"google.golang.org/protobuf/reflect/protodesc"
 	"google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
 	"google.golang.org/protobuf/runtime/protoimpl"
@@ -62,14 +63,7 @@ func FileDescriptor(s filePath) fileDescGZIP {
 	// Find the descriptor in the v2 registry.
 	var b []byte
 	if fd, _ := protoregistry.GlobalFiles.FindFileByPath(s); fd != nil {
-		if fd, ok := fd.(interface{ ProtoLegacyRawDesc() []byte }); ok {
-			b = fd.ProtoLegacyRawDesc()
-		} else {
-			// TODO: Use protodesc.ToFileDescriptorProto to construct
-			// a descriptorpb.FileDescriptorProto and marshal it.
-			// However, doing so causes the proto package to have a dependency
-			// on descriptorpb, leading to cyclic dependency issues.
-		}
+		b, _ = Marshal(protodesc.ToFileDescriptorProto(fd))
 	}
 
 	// Locally cache the raw descriptor form for the file.