doc/radosgw: remove "pubsub_event_lost"

Remove "pubsub_event_lost" from the list of "Notification Performance
Statistics" in doc/radosgw/notifications.rst. "pubsub_event_lost" is now
obsolete.

Fixes: https://tracker.ceph.com/issues/71790

Signed-off-by: Zac Dover <[email protected]>
(cherry picked from commit b308f50)

Author: zdover23

doc/radosgw/notifications.rst

@@ -126,16 +126,15 @@ Notification Performance Statistics
 -----------------------------------
 
 - ``pubsub_event_triggered``: a running counter of events that have at least one topic associated with them
-- ``pubsub_event_lost``: a running counter of events that had topics associated with them, but that were not pushed to any of the endpoints
 - ``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
 - ``pubsub_push_pending``: the gauge value of events pushed to an endpoint but not acked or nacked yet
 
 .. note::
 
-    ``pubsub_event_triggered`` and ``pubsub_event_lost`` are incremented per
-    event on each notification, but ``pubsub_push_ok`` and ``pubsub_push_fail``
-    are incremented per push action on each notification.
+    ``pubsub_event_triggered`` is incremented per event on each notification,
+    but ``pubsub_push_ok`` and ``pubsub_push_fail`` are incremented per push
+    action on each notification.
 
 Bucket Notification REST API
 ----------------------------