Container Registry UI/API "created_at" property yields null

Summary

The container registry API has a property "created_at". This property is currently coming back as null for my two images, even after rebuilding.

Steps to reproduce

curl --header "PRIVATE-TOKEN: <your_access_token>" \
     "https://gitlab.example.com/api/v4/projects/5/registry/repositories/2/tags/v10.0.0"

Example Project

sanin.dev/openrct2-docker

What is the current bug behavior?

"created_at" is null

What is the expected correct behavior?

"created_at" should be a timestamp

Relevant logs and/or screenshots

#> curl -s --header "PRIVATE-TOKEN: $TOKEN" "https://gitlab.com/api/v4/projects/20828950/registry/repositories/1343545/tags/develop"
{"name":"develop","path":"sanin.dev/openrct2-docker:develop","location":"registry.gitlab.com/sanin.dev/openrct2-docker:develop","revision":"086a274dce2564bf7d4f6fa2fbd9604bbc09a97caed0b9f1fa18f7a1232a42c3","short_revision":"086a274dc","digest":"sha256:8225298f56c7936c1facef3e75c8e0c32d8683b05c88db8aa2d2c5f987373ab2","created_at":null,"total_size":79972417}

Workaround

While this issue is not fixed, you can check the creation timestamp of an image using your registry client of choice. For example, using Docker CLI, you can do:

$ docker inspect -f '{{ .Created }}' registry.gitlab.com/path/to/image:tag
2021-11-24T20:19:40.483367546Z