Configure automatic cleanup of gitlab container registry storage for this project

TPA has just received an alert about the s3 bucket for the GitLab container registry reaching close to its quota in disk usage.

While investingating, we found out that this project is storing 64Gb or images in the container registry and automatic cleanup is currently not enabled.

It would be great to configure auto cleanup. However, we don't have a good idea for the required retention policy.

FYI there's some information here for how to view usage for the project: https://docs.gitlab.com/user/packages/container_registry/reduce_container_registry_storage/#for-a-project

and on the same documentation page, further down in the section titled "Create a cleanup policy" there's information about how to create the automatic cleanup configuration

/cc @lavamind