### 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)

)
ARG_RAW = Arg(("-r", "--raw"), argparse.SUPPRESS, "store_true")
ARG_IGNORE_ALL_DEPENDENCIES = Arg(
    ("-A", "--ignore-all-dependencies"),
    help="Ignores all non-critical dependencies, including ignore_ti_state and ignore_task_deps",
    action="store_true",
)
ARG_IGNORE_DEPENDENCIES = Arg(
    ("-i", "--ignore-dependencies"),
    help="Ignore task-specific dependencies, e.g. upstream, depends_on_past, and retry delay dependencies",
    action="store_true",
)
ARG_IGNORE_DEPENDS_ON_PAST = Arg(
    ("-I", "--ignore-depends-on-past"),
    help="Deprecated -- use `--depends-on-past ignore` instead. "
    "Ignore depends_on_past dependencies (but respect upstream dependencies)",
    action="store_true",
)
ARG_DEPENDS_ON_PAST = Arg(
    ("-d", "--depends-on-past"),
    help="Determine how Airflow should deal with past dependencies. The default action is `check`, Airflow "
    "will check if the the past dependencies are met for the tasks having `depends_on_past=True` before run "
    "them, if `ignore` is provided, the past dependencies will be ignored, if `wait` is provided and "
    "`depends_on_past=True`, Airflow will wait the past dependencies until they are met before running or "
    "skipping the task",
    choices={"check", "ignore", "wait"},
    default="check",
)
ARG_SHIP_DAG = Arg(
    ("--ship-dag",), help="Pickles (serializes) the DAG and ships it to the worker", action="store_true"