

**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
"""Historical getboolean"""
    warnings.warn(
        "Accessing configuration method 'getboolean' directly from the configuration module is "
        "deprecated. Please access the configuration from the 'configuration.conf' object via "
        "'conf.getboolean'",
        DeprecationWarning,
        stacklevel=2,
    )
    return conf.getboolean(*args, **kwargs)
def getfloat(*args, **kwargs):  
    """Historical getfloat"""
    warnings.warn(
        "Accessing configuration method 'getfloat' directly from the configuration module is "
        "deprecated. Please access the configuration from the 'configuration.conf' object via "
        "'conf.getfloat'",
        DeprecationWarning,
        stacklevel=2,
    )
    return conf.getfloat(*args, **kwargs)
def getint(*args, **kwargs):  
    """Historical getint"""
    warnings.warn(
        "Accessing configuration method 'getint' directly from the configuration module is "
        "deprecated. Please access the configuration from the 'configuration.conf' object via "
        "'conf.getint'",
        DeprecationWarning,
        stacklevel=2,
    )
    return conf.getint(*args, **kwargs)
def getsection(*args, **kwargs):