Merge pull request ceph#64138 from zdover23/wip-doc-2025-06-25-backport-64106-to-tentacle

tentacle: doc/radosgw: add "persistent_topic_size"

Reviewed-by: Anthony D'Atri <[email protected]>

Author: zdover23

doc/radosgw/notifications.rst

@@ -125,6 +125,7 @@ Dump (in JSON format) all pending bucket notifications of a persistent topic by
 Notification Performance Statistics
 -----------------------------------
 
+- ``persistent_topic_size``: queue size in bytes. 
 - ``pubsub_event_triggered``: a running counter of events that have at least one topic associated with them
 - ``pubsub_push_ok``: a running counter, for all notifications, of events successfully pushed to their endpoints
 - ``pubsub_push_fail``: a running counter, for all notifications, of events that failed to be pushed to their endpoints