Feature request: Keep specific versions

[MarkusRodler]

It would be nice that we can specify versions to keep. For example within the docker universe is package called latest which points to/contains the last stable version. For every push there will be at least one version added and the latest version updated.

At the moment the "latest" version will be deleted because it is the oldest created version.

[benjamin-koenig]

+1 for that.

I was thinking of something more advanced but our case is probably too special so I did not create a separate issue.

We would like to build a housekeeping workflow which cleans up package versions in all repositories of our organization. To avoid having to maintain a list of packages and versions to keep I was think about deleting all package versions for which there is no corresponding release. This way you could just delete the release and the package version will be eventually cleaned up as well.