Github client uses releases rather than packages for user repositories

The Github client implementation seems to use releases to infer tags for Github packages at the user scope. It may be the case that release tags and tags in a ghcr repo align, but that is not necessarily the case.

I think we should be using the Packages API rather than the Releases API.

https://docs.github.com/en/rest/packages/packages?apiVersion=2022-11-28#list-packages-for-a-user