Note: this will probably fail the existing CI, since I dropped the Makefile in favor of the two new test hooks. It's an unfortunate side-effect of the way Pagure's integration with Jenkins works; it won't recognize changes to the pipeline file from a PR.

Hopefully, going forward this new design should mean that is only an issue when we Branch a new Fedora, as updating the node label won't be reflected in the tests, but since we now run the ACTUAL tests under a docker image, it shouldn't matter that the node is still running on an older host OS.

FWIW, you can see a successful run of this new approach at https://jenkins-fedora-infra.apps.ci.centos.org/job/fedora-module-defaults-sgallagh/39/

Don't merge this just yet. I realized I want to make one additional change to handling PRs. Specifically that we want to ensure that we save the commit ID of the branch point so we can do comparisons, such as for the upcoming patch I'm working on to ensure that patches that change defaults update the modified value to avoid producing merge conflicts.