### Description

Currently, the `airflow variables export` command requires an explicit file path and does not support output to stdout. However connections can be printed to stdout using `airflow connections export -`. This inconsistency between the two export commands can lead to confusion and limits the flexibility of the variables export command.

### Use case/motivation

To bring some consistency, similar to connections, variables should also be printed to STDOUT, using `-` instead of filename. 

### Related issues

_No response_

### Are you willing to submit a PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

"""ClI command with subcommands."""
    name: str
    help: str
    subcommands: Iterable
    description: str | None = None
    epilog: str | None = None
CLICommand = Union[ActionCommand, GroupCommand]
DAGS_COMMANDS = (
    ActionCommand(
        name="details",
        help="Get DAG details given a DAG id",
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_details"),
        args=(ARG_DAG_ID, ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(
        name="list",
        help="List all the DAGs",
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_list_dags"),
        args=(ARG_SUBDIR, ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(
        name="list-import-errors",
        help="List all the DAGs that have import errors",
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_list_import_errors"),
        args=(ARG_SUBDIR, ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(
        name="report",
        help="Show DagBag loading report",