Cron job to delete old packages

We should be better about removing old packages that are no longer used.

We could use this GitHub Action https://github.com/actions/delete-package-versions

A good start might be to delete all but 5 versions of a package (to account for multiple PRs that could be open).

Packages and their info can be viewed here https://github.com/orgs/lifting-bits/packages?repo_name=cxx-common