Distro name is now `rhel-90` (was `rhel-90-ga`) Beta distro name is `rhel-90-beta` (was `rhel-90`)
All three "distros" share the same code for now. Adding manifests to track changes before updating the RHEL 9.0 GA definitions. Signed-off-by: Achilleas Koutsou <achilleas@koutsou.net>