Remove all gogoproto extensions

This commit removes the following gogoproto extensions;

- gogoproto.nullable
- gogoproto.customename
- gogoproto.unmarshaller_all
- gogoproto.stringer_all
- gogoproto.sizer_all
- gogoproto.marshaler_all
- gogoproto.goproto_unregonized_all
- gogoproto.goproto_stringer_all
- gogoproto.goproto_getters_all

None of them are supported by Google's toolchain (see #6564).

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

services/images/helpers.go

@@ -25,8 +25,8 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
-func imagesToProto(images []images.Image) []imagesapi.Image {
-	var imagespb []imagesapi.Image
+func imagesToProto(images []images.Image) []*imagesapi.Image {
+	var imagespb []*imagesapi.Image
 
 	for _, image := range images {
 		image := image
@@ -36,8 +36,8 @@ func imagesToProto(images []images.Image) []imagesapi.Image {
 	return imagespb
 }
 
-func imageToProto(image *images.Image) imagesapi.Image {
-	return imagesapi.Image{
+func imageToProto(image *images.Image) *imagesapi.Image {
+	return &imagesapi.Image{
 		Name:      image.Name,
 		Labels:    image.Labels,
 		Target:    descToProto(&image.Target),
@@ -50,7 +50,7 @@ func imageFromProto(imagepb *imagesapi.Image) images.Image {
 	return images.Image{
 		Name:      imagepb.Name,
 		Labels:    imagepb.Labels,
-		Target:    descFromProto(&imagepb.Target),
+		Target:    descFromProto(imagepb.Target),
 		CreatedAt: protobuf.FromTimestamp(imagepb.CreatedAt),
 		UpdatedAt: protobuf.FromTimestamp(imagepb.UpdatedAt),
 	}
@@ -65,8 +65,8 @@ func descFromProto(desc *types.Descriptor) ocispec.Descriptor {
 	}
 }
 
-func descToProto(desc *ocispec.Descriptor) types.Descriptor {
-	return types.Descriptor{
+func descToProto(desc *ocispec.Descriptor) *types.Descriptor {
+	return &types.Descriptor{
 		MediaType:   desc.MediaType,
 		Size_:       desc.Size,
 		Digest:      desc.Digest.String(),