Provide repo for RHEL9/AlmaLinux9

Red Hat Enterprise Linux 9 (RHEL 9) was released on 2022-05-18 and AlmaLinux 9 (binary compatible like CentOS (non stream) used to be) was released on 2022-05-26.

It would be really nice to have a gitlab-runner repo/packages for RHEL 9 or binary compatible operating systems, even if there is no gitlab-ee repo for RHEL 9 yet. Thanks!