Reduce the size of packages.gitlab.com bucket storage

We are generating quite a lot of costs for hosting our packages. Details can be found here: https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/12318#note_485923702

We should explore whether we can reduce these costs. While we are exploring whether we can automatically shift old content to lower tiers of object storage (https://gitlab.com/gitlab-com/gl-infra/production/-/issues/3334), we should also examine other avenues.

One possibility - nearly 50% of our packages are stored in the restricted pre-release repository. Do we need to keep all of these? It does seem like there is active use of this repo, but I imagine it is for the most recent packages?