Add Rocky Linux support to Foreman
I would like to contribute the "support" for Rocky Linux.
It is actually already working out of the box, just the logo is missing.
I also checked the licensing terms for the logos so this shouldn't be a problem. (https://github.com/rocky-linux/branding)
Also referencing the discussion in the forum: https://community.theforeman.org/t/client-recognition-for-rocky-linux-in-foreman-katello/23437