ARA's master branch now has static site generation, so we can move
away from the stable branch and get the new reports.
In the mean time ARA upstream has moved to github, so this updates the
references for the -devel job.
Depends-On: https://review.opendev.org/c/openstack/project-config/+/793530
Change-Id: I008b35562994f1205a4f66e53f93b9885a6b8754