fix: add support for uploaded index when signing using notation (#1882)

ci(notation): update to latest notation version
fix(sync): add layers info when syncing signatures

Signed-off-by: Andreea-Lupu <andreealupu1470@yahoo.com>

pkg/meta/parse.go

@@ -80,6 +80,10 @@ func ParseRepo(repo string, metaDB mTypes.MetaDB, storeController storage.StoreC
 	for _, descriptor := range indexContent.Manifests {
 		tag := descriptor.Annotations[ispec.AnnotationRefName]
 
+		if zcommon.IsReferrersTag(tag) {
+			continue
+		}
+
 		descriptorBlob, err := getCachedBlob(repo, descriptor, metaDB, imageStore, log)
 		if err != nil {
 			log.Error().Err(err).Msg("load-repo: error checking manifestMeta in MetaDB")
@@ -299,6 +303,11 @@ func getNotationSignatureLayersInfo(
 		return layers, err
 	}
 
+	// skip if is a notation index
+	if manifestContent.MediaType == ispec.MediaTypeImageIndex {
+		return []mTypes.LayerInfo{}, nil
+	}
+
 	if len(manifestContent.Layers) != 1 {
 		log.Error().Err(zerr.ErrBadManifest).Str("repository", repo).Str("reference", manifestDigest).
 			Msg("load-repo: notation signature manifest requires exactly one layer but it does not")