

**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
option = self._get_env_var_option(section, key)
        if option is not None:
            return option
        if deprecated_section:
            option = self._get_env_var_option(deprecated_section, deprecated_key)
            if option is not None:
                self._warn_deprecate(section, key, deprecated_section, deprecated_key)
                return option
        return None
    def getboolean(self, section, key, **kwargs):
        val = str(self.get(section, key, **kwargs)).lower().strip()
        if '#' in val:
            val = val.split('#')[0].strip()
        if val in ('t', 'true', '1'):
            return True
        elif val in ('f', 'false', '0'):
            return False
        else:
            raise AirflowConfigException(
                f'Failed to convert value to bool. Please check "{key}" key in "{section}" section. '
                f'Current value: "{val}".'
            )
    def getint(self, section, key, **kwargs):