New cron.* maintenance to cleanup action job/run/task tables

[nicorac]

Feature Description

I'm testing the new Gitea Actions feature (I know, it's still a preview, but it works great for me...) and I've filled up Actions log with hundreds of (now useless) test runs.
I see there's no way to cleanup them other than straight access to DB.

The existing cron.delete_old_actions only deletes repo user actions (like pushes, issue close, ...) but does not cleanup the CI/CD Actions log.

Should be great to have a new maintenance job to cleanup actions_job, actions_run and action_task tables as like as the existing cron.delete_old_actions maintenance task cleans up the actions table.

I think there's no need to keep that history forever, at least in small & personal Gitea instances.

An alternative could be to extend the existing cron.delete_old_actions task to cleanup those tables too, maybe with different run parameters.

[wolfogre]

I think it's duplicated with #24256.