

**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/cli/cli_parser.py
("-u", "--umask"),
    help="Set the umask of celery worker in daemon mode",
    default=conf.get('celery', 'worker_umask'),
)
ARG_WITHOUT_MINGLE = Arg(
    ("--without-mingle",),
    default=False,
    help="Don’t synchronize with other workers at start-up",
    action="store_true",
)
ARG_WITHOUT_GOSSIP = Arg(
    ("--without-gossip",),
    default=False,
    help="Don’t subscribe to other workers events",
    action="store_true",
)
# flower
ARG_BROKER_API = Arg(("-a", "--broker-api"), help="Broker API")
ARG_FLOWER_HOSTNAME = Arg(
    ("-H", "--hostname"),
    default=conf.get('celery', 'FLOWER_HOST'),
    help="Set the hostname on which to run the server",
)
ARG_FLOWER_PORT = Arg(
    ("-p", "--port"),
    default=conf.get('celery', 'FLOWER_PORT'),
    type=int,
    help="The port on which to run the server",
)
ARG_FLOWER_CONF = Arg(("-c", "--flower-conf"), help="Configuration file for flower")