Implement worker that `hard-deletes` old CI jobs metadata

Currently, we implemented the [Deprecate retention of build metadata older than 3 months (gitlab-foss#50939 (closed)).

This after a specified period allows us to disable ability for jobs to be retried. In such cases they are marked as archived and cannot be triggered. This does not prevent trigger the whole pipeline for a given commit, but this makes this pipeline to loose some metadata to be removed:

• metadata of individual builds
• DAG dependencies
• etc.

The above is based on assumption, after some period you do not really care about being able to retry an individual job. You can still trigger the whole pipeline. Holding all these data is storage intensive as DB is not infinitely scalable.

This is the first step, as we implemented soft-delete (we disallow, but do not remove actual data).

Next step would be to start hard-delete of these data, after they hit a deadline. This allows us to remove a substantial amount of data from Database, and make the whole system significantly more healthy.

I would assume that we would introduce some worker that would walk the table and delete these entries. This worker likely would be executed once a month or even less frequently.