fix(repodb): GQL request for ExpandedRepoInfo errors when artifacts with tags are present (#1265)

If we push an artifact and give it a tag, repodb would crash because of the null pointer dereferencing

Now when iterating over the tags of a repo and stumbling upon a unsupported media type, it's being ignored

Signed-off-by: Laurentiu Niculae <niculae.laurentiu1@gmail.com>

pkg/test/common_test.go

@@ -241,7 +241,7 @@ func TestUploadArtifact(t *testing.T) {
 
 		artifact := ispec.Artifact{}
 
-		err := test.UploadArtifactManifest(&artifact, baseURL, "test")
+		err := test.UploadArtifactManifest(&artifact, nil, baseURL, "test")
 		So(err, ShouldNotBeNil)
 	})
 }