mgr/rook: adding empty calls to upgrade_ls and upgrade_status

mgr/rook: adding empty calls to upgrade_ls and upgrade_status

added empty calls to upgrade_ls and upgrade_status to avoid
dashboard errors when entering the view Cluster > Upgrade. Empty
calls are used because we don't support the upgrade functionality
in rook as we do for normal Ceph deployments. In case of rook user
has to follow a different process to upgrade Ceph.

Fixes: https://tracker.ceph.com/issues/64516
Signed-off-by: Redouane Kachach <rkachach@redhat.com>