Some minor performance fixes for task schedular

synapse/util/task_scheduler.py

@@ -352,6 +352,9 @@ async def wrapper() -> None:
                 )
                 self._running_tasks.remove(task.id)
 
+            # Try launch a new task since we've finished with this one.
+            self._clock.call_later(1, self._launch_scheduled_tasks)
+
         if len(self._running_tasks) >= TaskScheduler.MAX_CONCURRENT_RUNNING_TASKS:
             return