Stop sirbot

async def _stop(self, app) -> None:
        """
        Stop sirbot
        """
        logger.info('Stopping Sir Bot-a-lot ...')

        for task in self._tasks.values():
            task.cancel()
        await asyncio.gather(*self._tasks.values(), loop=self._loop)
        await self._session.close()

        logger.info('Sir Bot-a-lot fully stopped')