Migrate GitLab to the new container registry metadata database

In #41604 (closed) we identified a load issue on GitLab where container registry cleanup jobs would cause a continuous spike in the number of Sidekiq / Redis jobs.

As a mitigation, we disabled container cleanup policies in tpo/web/donate-neo and reduced the number of container registry cleanup workers.

However the long-term solution is to migrate to the next-gen container registry metadata database. As of GitLab 17.1, this feature is out of beta, so we can move forward on this.

The migration process is documented here: Enable the metadata database for Linux package installations. The one-step migration should be appropriate for our installation.