### 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)

" " * 4,
    ),
)
ARG_USER_EXPORT = Arg(("export",), metavar="FILEPATH", help="Export all users to JSON file")
ARG_CREATE_ROLE = Arg(("-c", "--create"), help="Create a new role", action="store_true")
ARG_LIST_ROLES = Arg(("-l", "--list"), help="List roles", action="store_true")
ARG_ROLES = Arg(("role",), help="The name of a role", nargs="*")
ARG_PERMISSIONS = Arg(("-p", "--permission"), help="Show role permissions", action="store_true")
ARG_ROLE_RESOURCE = Arg(("-r", "--resource"), help="The name of permissions", nargs="*", required=True)
ARG_ROLE_ACTION = Arg(("-a", "--action"), help="The action of permissions", nargs="*")
ARG_ROLE_ACTION_REQUIRED = Arg(("-a", "--action"), help="The action of permissions", nargs="*", required=True)
ARG_AUTOSCALE = Arg(("-a", "--autoscale"), help="Minimum and Maximum number of worker to autoscale")
ARG_SKIP_SERVE_LOGS = Arg(
    ("-s", "--skip-serve-logs"),
    default=False,
    help="Don't start the serve logs process along with the workers",
    action="store_true",
)
ARG_ROLE_IMPORT = Arg(("file",), help="Import roles from JSON file", nargs=None)
ARG_ROLE_EXPORT = Arg(("file",), help="Export all roles to JSON file", nargs=None)
ARG_ROLE_EXPORT_FMT = Arg(
    ("-p", "--pretty"),
    help="Format output JSON file by sorting role names and indenting by 4 spaces",
    action="store_true",
)
ARG_ANONYMIZE = Arg(
    ("--anonymize",),
    help="Minimize any personal identifiable information. Use it when sharing output with others.",
    action="store_true",
)