[3.13] gh-136697: Use the standard audit event format for sys.monitoring docs (GH-136747)

(cherry picked from commit 28937d3)

Co-authored-by: Tian Gao <gaogaotiantian@hotmail.com>

Author: gaogaotiantian

Doc/library/sys.monitoring.rst

@@ -314,13 +314,17 @@ To register a callable for events call
    it is unregistered and returned.
    Otherwise :func:`register_callback` returns ``None``.
 
+   .. audit-event:: sys.monitoring.register_callback func sys.monitoring.register_callback
 
 Functions can be unregistered by calling
 ``sys.monitoring.register_callback(tool_id, event, None)``.
 
 Callback functions can be registered and unregistered at any time.
 
-Registering or unregistering a callback function will generate a :func:`sys.audit` event.
+Callbacks are called only once regardless if the event is turned on both
+globally and locally. As such, if an event could be turned on for both global
+and local events by your code then the callback needs to be written to handle
+either trigger.
 
 
 Callback function arguments