Remove support /-/kubernetes-agent from Omnibus
This can only be done on a major release, and needs to wait for the 2 linked MRs to be merged.
Once #5784 (closed) is merged, we don't need to keep supporting this endpoint anymore. This removal makes sense as it's the same direction that we've already took on the GitLab chart. We don't support this endpoint there anymore.
Edited by João Alexandre Cunha