- Add a cron job and a limited capacity worker to delete package files
  in a decoupled and async way, taking the Package Registry a step
  closer to a scalable package file deletion approach.
- The cron job runs twice a day. It checks if there are any package
  files pending destruction, in which case it enqueues the limited
  capacity worker.
- The limited capacity worker picks up and destroys package files that
  are pending destruction one by one until all have ben deleted.
- Since the new jobs are very similar in functionality to the Dependency
  Proxy cleanup jobs, do some refactoring for reuse.

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77212
Changelog: other