Delete deploy-cleanup-old-deleted-files-manual job

What does this MR do?

Delete manual job to perform cleanup of prod files (leave the scheduled one), it has unintended side effect of making a deploy to prod button show up, which could be incorrectly used to deploy an old version to production. See slack thread. If it ever needs to be run urgently or on demand, it can still be run manually via the CI schedule interface.

Related issues

Closes