### 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_DB_FROM_REVISION = Arg(
    ("--from-revision",),
    help="(Optional) If generating sql, may supply a *from* Alembic revision",
)
ARG_DB_SQL_ONLY = Arg(
    ("-s", "--show-sql-only"),
    help="Don't actually run migrations; just print out sql scripts for offline migration. "
    "Required if using either `--from-revision` or `--from-version`.",
    action="store_true",
    default=False,
)
ARG_DB_SKIP_INIT = Arg(
    ("-s", "--skip-init"),
    help="Only remove tables; do not perform db init.",
    action="store_true",
    default=False,
)
ARG_PORT = Arg(
    ("-p", "--port"),
    default=conf.get("webserver", "WEB_SERVER_PORT"),
    type=int,
    help="The port on which to run the server",
)
ARG_SSL_CERT = Arg(
    ("--ssl-cert",),
    default=conf.get("webserver", "WEB_SERVER_SSL_CERT"),
    help="Path to the SSL certificate for the webserver",
)
ARG_SSL_KEY = Arg(