

**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
self, content: Any, context: Dict, jinja_env: jinja2.Environment, seen_oids: Set
    ) -> None:
        if id(content) not in seen_oids:
            seen_oids.add(id(content))
            try:
                nested_template_fields = content.template_fields
            except AttributeError:
                
                return
            self._do_render_template_fields(content, nested_template_fields, context, jinja_env, seen_oids)
    def get_template_env(self) -> jinja2.Environment:
        """Fetch a Jinja template environment from the DAG or instantiate empty environment if no DAG."""
        return self.dag.get_template_env() if self.has_dag() else jinja2.Environment(cache_size=0)  
    def prepare_template(self) -> None:
        """
        Hook that is triggered after the templated fields get replaced
        by their content. If you need your operator to alter the
        content of the file before the template is rendered,
        it should override this method to do so.
        """
    def resolve_template_files(self) -> None: