Merge PR #26345 into master

* refs/pull/26345/head:
	ceph-osd: be helpful about upgrade gate
	mon: record 'min_mon_release' file and prevent startup if it's too old
	mon/Monitor: do not join cluster that is >2 releases old
	mon/Elector: respect monmap min_mon_release
	mon: check min_mon_release during probe
	mon/MonmapMonitor: increase min_mon_release when full quorum is upgraded
	mon: maintain quorum_min_mon_release
	mon/MonMapMonitor: set initial min_mon_release
	monmaptool: add --set-min-mon-release
	monmaptool: don't spew usage on any error
	mon/MonMap: add min_mon_release field

Reviewed-by: Kefu Chai <kchai@redhat.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>

diff --cc src/ceph_mon.cc
Simple merge

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