Ansible-test community images: CentOS Stream 8 image no longer updated

Since CentOS Stream 8 is now End of Life, we released one final version of the community ansible-test image with modified yum baseurl so that installing packages should still work, and then removed it completely from the build. If you are using that image, consider removing it from CI, or switching to a different one.

(PS: if someone is interested in contributing an image for Rocky Linux or Alma Linux to GitHub - ansible-community/images: Ansible container image definitions meant for ansible-test and Execution Environments, that would be great :slight_smile: Right now there is no ansible-test Docker image for anything RHEL-like except Fedora, which limits testing collections on GHA considerably IMO.)