Merge pull request #60563 from rishabh-d-dave/wip-68679-reef

reef: mgr: allow disabling always-on modules

diff --cc PendingReleaseNotes
Simple merge

diff --cc qa/cephfs/overrides/ignorelist_health.yaml
Simple merge

diff --cc qa/tasks/cephfs/test_admin.py
Simple merge

diff --cc src/mon/MgrMonitor.cc
Simple merge

diff --cc src/mon/MonCommands.h
Simple merge