build: go 1.24

We were running behind and there were quite some deprecations to update.
This was mostly in the upstream copy/pasta package but seems quite
minimal.

vendor/github.com/google/go-cmp/cmp/internal/function/func.go

@@ -19,6 +19,7 @@ const (
 
 	tbFunc  // func(T) bool
 	ttbFunc // func(T, T) bool
+	ttiFunc // func(T, T) int
 	trbFunc // func(T, R) bool
 	tibFunc // func(T, I) bool
 	trFunc  // func(T) R
@@ -28,11 +29,13 @@ const (
 	Transformer       = trFunc  // func(T) R
 	ValueFilter       = ttbFunc // func(T, T) bool
 	Less              = ttbFunc // func(T, T) bool
+	Compare           = ttiFunc // func(T, T) int
 	ValuePredicate    = tbFunc  // func(T) bool
 	KeyValuePredicate = trbFunc // func(T, R) bool
 )
 
 var boolType = reflect.TypeOf(true)
+var intType = reflect.TypeOf(0)
 
 // IsType reports whether the reflect.Type is of the specified function type.
 func IsType(t reflect.Type, ft funcType) bool {
@@ -49,6 +52,10 @@ func IsType(t reflect.Type, ft funcType) bool {
 		if ni == 2 && no == 1 && t.In(0) == t.In(1) && t.Out(0) == boolType {
 			return true
 		}
+	case ttiFunc: // func(T, T) int
+		if ni == 2 && no == 1 && t.In(0) == t.In(1) && t.Out(0) == intType {
+			return true
+		}
 	case trbFunc: // func(T, R) bool
 		if ni == 2 && no == 1 && t.Out(0) == boolType {
 			return true

vendor/github.com/google/go-cmp/cmp/options.go

@@ -232,7 +232,15 @@ func (validator) apply(s *state, vx, vy reflect.Value) {
 		if t := s.curPath.Index(-2).Type(); t.Name() != "" {
 			// Named type with unexported fields.
 			name = fmt.Sprintf("%q.%v", t.PkgPath(), t.Name()) // e.g., "path/to/package".MyType
-			if _, ok := reflect.New(t).Interface().(error); ok {
+			isProtoMessage := func(t reflect.Type) bool {
+				m, ok := reflect.PointerTo(t).MethodByName("ProtoReflect")
+				return ok && m.Type.NumIn() == 1 && m.Type.NumOut() == 1 &&
+					m.Type.Out(0).PkgPath() == "google.golang.org/protobuf/reflect/protoreflect" &&
+					m.Type.Out(0).Name() == "Message"
+			}
+			if isProtoMessage(t) {
+				help = `consider using "google.golang.org/protobuf/testing/protocmp".Transform to compare proto.Message types`
+			} else if _, ok := reflect.New(t).Interface().(error); ok {
 				help = "consider using cmpopts.EquateErrors to compare error values"
 			} else if t.Comparable() {
 				help = "consider using cmpopts.EquateComparable to compare comparable Go types"