### 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.
help="Kubernetes Namespace. Default value is `[kubernetes] namespace` in configuration.",
)
ARG_MIN_PENDING_MINUTES = Arg(
    ("--min-pending-minutes",),
    default=30,
    type=positive_int(allow_zero=False),
    help=(
        "Pending pods created before the time interval are to be cleaned up, "
        "measured in minutes. Default value is 30(m). The minimum value is 5(m)."
    ),
)
ARG_JOB_TYPE_FILTER = Arg(
    ("--job-type",),
    choices=("BackfillJob", "LocalTaskJob", "SchedulerJob", "TriggererJob", "DagProcessorJob"),
    action="store",
    help="The type of job(s) that will be checked.",
)
ARG_JOB_HOSTNAME_FILTER = Arg(
    ("--hostname",),
    default=None,
    type=str,
    help="The hostname of job(s) that will be checked.",
)
ARG_JOB_HOSTNAME_CALLABLE_FILTER = Arg(
    ("--local",),
    action="store_true",
    help="If passed, this command will only show jobs from the local host "
    "(those with a hostname matching what `hostname_callable` returns).",
)
ARG_JOB_LIMIT = Arg(