Merge pull request #48398 from rhcs-dashboard/fix-get-rbd-stats

mgr/prometheus: avoid duplicates and deleted entries for rbd_stats_pools

Reviewed-by: Aashish Sharma <aasharma@redhat.com>
Reviewed-by: Ernesto Puerta <epuertat@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@redhat.com>
Reviewed-by: Radoslaw Zarzynski <rzarzyns@redhat.com>

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