Setup permissions so that we can read the kube-system namespace to get its UID.

Prefect uses the `kube-system` namespace to get the UID for job identification purpose. 

See the discussion here: https://prefect-community.slack.com/archives/CL09KU1K7/p1670585894619609?thread_ts=1670582075.035229&cid=CL09KU1K7 