mgr/cephadm: fix check for if devices have changed

mgr/cephadm: fix check for if devices have changed

Directly comparing the dicts doesn't work since the
"created" field was added in. We should instead make use
of the existing Devices equality function.

Fixes: https://tracker.ceph.com/issues/57999
Signed-off-by: Adam King <adking@redhat.com>
(cherry picked from commit 55661cc859a5160822b5293f7cc49d6fdb5b715d)

Conflicts:
	src/pybind/mgr/cephadm/tests/test_cephadm.py