

**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/configuration.py
for (source_name, config) in configs:
            for section in config.sections():
                AirflowConfigParser._replace_section_config_with_display_sources(
                    config, config_sources, display_source, raw, section, source_name
                )
    @staticmethod
    def _replace_section_config_with_display_sources(