Cleanup cache images

[viceice]

We don't need the old untagged images anymore, they where only saved for caching purposes.
We need to use the github api.

https://github.com/renovatebot/docker-build-cache/pkgs/container/docker-build-cache/versions

Currently visiting the package leads to unicorn errors.

[viceice]

something like: https://github.com/rafalkk/remove-dockertag-action/blob/main/action.yml

[viceice]

• Cleanup cache images containerbase/docker-build-cache#2

[viceice]

https://github.com/airtower-luna/hello-ghcr/blob/main/.github/workflows/prune_images.yaml