Merge pull request #45174 from adk3798/no-drain-admin

mgr/cephadm: block draining last _admin host

Reviewed-by: Michael Fritch <mfritch@suse.com>
Reviewed-by: Nizamudeen A <nia@redhat.com>

diff --cc src/pybind/mgr/cephadm/module.py
Simple merge

diff --cc src/pybind/mgr/orchestrator/_interface.py
Simple merge

diff --cc src/pybind/mgr/orchestrator/module.py
Simple merge