### 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_RESERIALIZE_DAGS = Arg(
    ("--no-reserialize-dags",),
    
    help=argparse.SUPPRESS,
    action="store_false",
    default=True,
    dest="reserialize_dags",
)
ARG_DB_VERSION__UPGRADE = Arg(
    ("-n", "--to-version"),
    help=(
        "(Optional) The airflow version to upgrade to. Note: must provide either "
        "`--to-revision` or `--to-version`."
    ),
)
ARG_DB_REVISION__UPGRADE = Arg(
    ("-r", "--to-revision"),
    help="(Optional) If provided, only run migrations up to and including this Alembic revision.",
)
ARG_DB_VERSION__DOWNGRADE = Arg(
    ("-n", "--to-version"),
    help="(Optional) If provided, only run migrations up to this version.",
)
ARG_DB_FROM_VERSION = Arg(
    ("--from-version",),
    help="(Optional) If generating sql, may supply a *from* version",
)
ARG_DB_REVISION__DOWNGRADE = Arg(
    ("-r", "--to-revision"),
    help="The Alembic revision to downgrade to. Note: must provide either `--to-revision` or `--to-version`.",