### 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.
default=False,
)
ARG_OUTPUT = Arg(
    (
        "-o",
        "--output",
    ),
    help="Output format. Allowed values: json, yaml, plain, table (default: table)",
    metavar="(table, json, yaml, plain)",
    choices=("table", "json", "yaml", "plain"),
    default="table",
)
ARG_COLOR = Arg(
    ("--color",),
    help="Do emit colored output (default: auto)",
    choices={ColorMode.ON, ColorMode.OFF, ColorMode.AUTO},
    default=ColorMode.AUTO,
)
ARG_VERSION_RANGE = Arg(
    ("-r", "--range"),
    help="Version range(start:end) for offline sql generation. Example: '2.0.2:2.2.3'",
    default=None,
)
ARG_REVISION_RANGE = Arg(
    ("--revision-range",),
    help=(
        "Migration revision range(start:end) to use for offline sql generation. "
        "Example: ``a13f7613ad25:7b2661a43ba3``"
    ),
    default=None,