### 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)

("--job-type",),
    choices=("BackfillJob", "LocalTaskJob", "SchedulerJob", "TriggererJob", "DagProcessorJob"),
    action="store",
    help="The type of job(s) that will be checked.",
)
ARG_JOB_HOSTNAME_FILTER = Arg(
    ("--hostname",),
    default=None,
    type=str,
    help="The hostname of job(s) that will be checked.",
)
ARG_JOB_HOSTNAME_CALLABLE_FILTER = Arg(
    ("--local",),
    action="store_true",
    help="If passed, this command will only show jobs from the local host "
    "(those with a hostname matching what `hostname_callable` returns).",
)
ARG_JOB_LIMIT = Arg(
    ("--limit",),
    default=1,
    type=positive_int(allow_zero=True),
    help="The number of recent jobs that will be checked. To disable limit, set 0. ",
)
ARG_ALLOW_MULTIPLE = Arg(
    ("--allow-multiple",),
    action="store_true",
    help="If passed, this command will be successful even if multiple matching alive jobs are found.",
)
ARG_INCLUDE_DAGS = Arg(
    ("--include-dags",), help="If passed, DAG specific permissions will also be synced.", action="store_true"