Much-belated cleanup
    
    - remove all references to cgroups v1. That code never worked,
      and "cgroups v2" in test names was misleading because it
      implied an alternative. Remove it.
    - refactor podman remote and local tests
    - clean up docs
    - Ansible bitrot cleanup ("this is deprecated, use that")
    
    Tested using 1minutetip but even so this is a big change and
    we need to be prepared for fallout in the next bodhi.
    
    Signed-off-by: Ed Santiago <santiago@redhat.com>