https://github.com/apache/airflow/pull/27892 added Internal API as part of Webserver.

We need to introduce `airlfow internal-api` CLI command that starts Internal API as a independent component.
"""Create a lazy loader for command."""
    _, _, name = import_path.rpartition(".")
    def command(*args, **kwargs):
        func = import_string(import_path)
        return func(*args, **kwargs)
    command.__name__ = name
    return command
class DefaultHelpParser(argparse.ArgumentParser):
    """CustomParser to display help message."""
    def _check_value(self, action, value):
        """Override _check_value and check conditionally added command."""
        if action.dest == "subcommand" and value == "celery":
            executor = conf.get("core", "EXECUTOR")
            if executor not in (CELERY_EXECUTOR, CELERY_KUBERNETES_EXECUTOR):
                executor_cls, _ = ExecutorLoader.import_executor_cls(executor)
                classes = ()
                try:
                    from airflow.executors.celery_executor import CeleryExecutor
                    classes += (CeleryExecutor,)
                except ImportError:
                    message = (
                        "The celery subcommand requires that you pip install the celery module. "
                        "To do it, run: pip install 'apache-airflow[celery]'"
                    )
                    raise ArgumentError(action, message)