### 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.
("--limit",),
    default=1,
    type=positive_int(allow_zero=True),
    help="The number of recent jobs that will be checked. To disable limit, set 0. ",
)
ARG_ALLOW_MULTIPLE = Arg(
    ("--allow-multiple",),
    action="store_true",
    help="If passed, this command will be successful even if multiple matching alive jobs are found.",
)
ARG_CAPACITY = Arg(
    ("--capacity",),
    type=positive_int(allow_zero=False),
    help="The maximum number of triggers that a Triggerer will run at one time.",
)
ARG_CLEAR_ONLY = Arg(
    ("--clear-only",),
    action="store_true",
    help="If passed, serialized DAGs will be cleared but not reserialized.",
)
ALTERNATIVE_CONN_SPECS_ARGS = [
    ARG_CONN_TYPE,
    ARG_CONN_DESCRIPTION,
    ARG_CONN_HOST,
    ARG_CONN_LOGIN,
    ARG_CONN_PASSWORD,
    ARG_CONN_SCHEMA,
    ARG_CONN_PORT,
]
class ActionCommand(NamedTuple):