Support Rocky Linux 9 as OS

[embik]

What it says on the title. I'm not sure exactly what is required since I haven't checked what has changed in Rocky Linux 9, but we should work on supporting it eventually.

This requires support in OSM as well.

[xrstf]

I have run KKP conformance tests against RockyLinux 9.4 on vSphere. Worked like a charm.

[rajaSahil]

/assign