Description of problem:

RHEL is considering a change to cease publishing uncompressed comps.xml metadata in the future. While this is unlikely to happen soon, we need to stop expecting package groups metadata to be available in uncompressed form. Likewise we should produce both types of metadata to maintain compatibility with all releases.

https://bugzilla.redhat.com/show_bug.cgi?id=2056318

Version-Release number of selected component (if applicable): any

How reproducible:100%

Steps to Reproduce:
1. Produce a repository with package groups but without a raw comps.xml file. This might require manual modification as I believe createrepo_c typically creates both.
2. Sync it
3. The package group metadata (comps.xml) isn't processed and isn't available after republishing

Expected results:

It should be available and contain equivalent metadata as when it was synced. Depending on our implementation decisions we should possibly produce both compressed and uncompressed comps metadata (TBD)

Additional info: