Context manager that yields an instance of ``Producer``.

def create_producer(self):
        """Context manager that yields an instance of ``Producer``."""
        with current_celery_app.pool.acquire(block=True) as conn:
            yield Producer(
                conn,
                exchange=self.mq_exchange,
                routing_key=self.mq_routing_key,
                auto_declare=True,
            )