Temporarily disable task gathering at connection close

... to investigate the blockage in the CI, gathering "all_tasks" might
be problematic.

Author: cderici

juju/client/connection.py

@@ -451,13 +451,16 @@ async def close(self, to_reconnect=False):
         if self._ws and not self._ws.closed:
             await self._ws.close()
 
+        """
+        Temporarily disabling this to investigate CI blockage
         try:
             log.debug('Gathering all tasks for connection close')
             await jasyncio.gather(*jasyncio.all_tasks())
         except jasyncio.CancelledError:
             pass
         except websockets.exceptions.ConnectionClosed:
             pass
+        """
 
         self._pinger_task = None
         self._receiver_task = None