WTH can't I delete old backups with an action?

Very happy with the new action several months back that lets you automatically trigger a backup of your HA server. I set up an automation that does the right daily, monthly, quarterly, yearly backups each night.

Now I’d like an action for removing old backups automatically, e.g. only keep N backups in a given backup folder, or the ability to tag a backup and delete the oldest backup with a given tag.

I can do this currently just by deleting backup files on my NAS, but it would be nice to be able to do it more easily from within HA.