### 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_UPSTREAM,
            ARG_DOWNSTREAM,
            ARG_YES,
            ARG_ONLY_FAILED,
            ARG_ONLY_RUNNING,
            ARG_EXCLUDE_SUBDAGS,
            ARG_EXCLUDE_PARENTDAG,
            ARG_DAG_REGEX,
            ARG_VERBOSE,
        ),
    ),
    ActionCommand(
        name="state",
        help="Get the status of a task instance",
        func=lazy_load_command("airflow.cli.commands.task_command.task_state"),
        args=(
            ARG_DAG_ID,
            ARG_TASK_ID,
            ARG_EXECUTION_DATE_OR_RUN_ID,
            ARG_SUBDIR,
            ARG_VERBOSE,
            ARG_MAP_INDEX,
        ),
    ),
    ActionCommand(
        name="failed-deps",
        help="Returns the unmet dependencies for a task instance",
        description=(
            "Returns the unmet dependencies for a task instance from the perspective of the scheduler. "
            "In other words, why a task instance doesn't get scheduled and then queued by the scheduler, "