Test for naming conflicts in the opensuse/ namespace

[dirkmueller]

There could be a container submitted into openSUSE Tumbleweed that publishes under registry.opensuse.org/opensuse/* under the same name like BCI-dockerfile-generated containers. we might want to have an automated test somewhere that identifies those clashes and highlights/notifies the team on the conflict so that it can be manually resolved somehow.

As discussed in BCI-sync 06-04

[Vogtinator]

It's not that easy:

1. It's explicitly supported that tags move between containers over time (e.g. unstable -> stable -> oldstable)
2. Some tags are provided by multiple containers (e.g. python-3.10-image, python-3.11-image and python-3.12-image all provide opensuse/bci/python:3)

1 means we can't just query the registry for whatever is published, but need to ask OBS what's currently in openSUSE:Factory. I'm not aware of an API that returns tags based on project/repo/arch and fetching+parsing .containerinfo of all binaries does not scale.

2 means there will be false positives and it can't effectively be automated.