### Body

The CLI:

`airflow variables set [-h] [-j] [-v] key VALUE`

https://airflow.apache.org/docs/apache-airflow/stable/cli-and-env-variables-ref.html#set_repeat1

Doesn't support adding description though column exists and we support it from Rest API:
https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html#operation/post_variables

**The Task:**

Allow to set description from cli command

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
ARG_STDERR,
            ARG_LOG_FILE,
            ARG_VERBOSE,
        ),
    ),
    ActionCommand(
        name="version",
        help="Show the version",
        func=lazy_load_command("airflow.cli.commands.version_command.version"),
        args=(),
    ),
    ActionCommand(
        name="cheat-sheet",
        help="Display cheat sheet",
        func=lazy_load_command("airflow.cli.commands.cheat_sheet_command.cheat_sheet"),
        args=(ARG_VERBOSE,),
    ),
    GroupCommand(
        name="connections",
        help="Manage connections",
        subcommands=CONNECTIONS_COMMANDS,
    ),
    GroupCommand(
        name="providers",
        help="Display providers",
        subcommands=PROVIDERS_COMMANDS,
    ),
    ActionCommand(
        name="rotate-fernet-key",
        func=lazy_load_command("airflow.cli.commands.rotate_fernet_key_command.rotate_fernet_key"),