Delete actors after stopping them

Signed-off-by: Mathias L. Baumann <[email protected]>

Author: Marenz

src/frequenz/dispatch/_actor_dispatcher.py

@@ -282,6 +282,8 @@ async def _stop_actor(self, stopping_dispatch: Dispatch, msg: str) -> None:
 
         if actor:
             await actor.stop(msg)
+
+            del self._actors[identity]
         else:
             _logger.warning(
                 "Actor for dispatch type %r is not running", stopping_dispatch.type