gitlab compute minutes warning (quota almost reached)

Now that CentOS SIGs are all using Gitlab (under https://gitlab.com/CentOS) , we got today a warning from gitlab about our free-tier quota for compute minutes (shared runners) almost reached. We should investigate some options about this (eventually hosting ourselves on AWS some shared/group runners) to avoid some CI/CD jobs to fail when quota will be reached.

Also engaging with SIGs on the devel list about that , for awareness, and so discussing all together