Apply suggestions from review

Co-authored-by: David Brochart <[email protected]>

pycrdt_websocket/yroom.py

@@ -213,6 +213,7 @@ async def start(
             self._task_group.start_soon(self._stopped.wait)
             self._task_group.start_soon(self._watch_ready)
             self._task_group.start_soon(self._broadcast_updates)
+            self._task_group.start_soon(self.awareness.start)
             return
 
         async with self._start_lock:
@@ -241,7 +242,7 @@ async def stop(self) -> None:
         if self._task_group is None:
             raise RuntimeError("YRoom not running")
         self._stopped.set()
-        self.awareness.stop()
+        await self.awareness.stop()
         self._task_group.cancel_scope.cancel()
         self._task_group = None
         if self._subscription is not None: