Get rid of client.loop

Instead, use the asyncio-intended way of implicit loop.

telethon/_client/chats.py

@@ -40,7 +40,7 @@ class _ChatAction:
             self._chat, self._action)
 
         self._running = True
-        self._task = self._client.loop.create_task(self._update())
+        self._task = asyncio.create_task(self._update())
         return self
 
     async def __aexit__(self, *args):