

**Description**

We are using a 3rd party executor which has the ability to use multiple queues, however the `default_queue` is defined under the `celery` heading and is used regardless of the executor that you are using.

See: https://github.com/apache/airflow/blob/2.0.1/airflow/models/baseoperator.py#L366

It would be nice to decouple the default_queue configuration argument away from the celery section to allow other executors to utilise this functionality with less confusion.

**Are you willing to submit a PR?**

Yep! Will open a pull request shortly


**Related Issues**

Not that I'm aware of.

airflow/models/baseoperator.py
"""@property: list of tasks directly upstream"""
        return [self.dag.get_task(tid) for tid in self._upstream_task_ids]
    @property
    def upstream_task_ids(self) -> Set[str]:
        """@property: set of ids of tasks directly upstream"""
        return self._upstream_task_ids
    @property
    def downstream_list(self) -> List["BaseOperator"]:
        """@property: list of tasks directly downstream"""
        return [self.dag.get_task(tid) for tid in self._downstream_task_ids]
    @property
    def downstream_task_ids(self) -> Set[str]:
        """@property: set of ids of tasks directly downstream"""
        return self._downstream_task_ids
    @provide_session
    def clear(