### 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.
name="state",
        help="Get the status of a dag run",
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_state"),
        args=(ARG_DAG_ID, ARG_EXECUTION_DATE, ARG_SUBDIR, ARG_VERBOSE),
    ),
    ActionCommand(
        name="next-execution",
        help="Get the next execution datetimes of a DAG",
        description=(
            "Get the next execution datetimes of a DAG. It returns one execution unless the "
            "num-executions option is given"
        ),
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_next_execution"),
        args=(ARG_DAG_ID, ARG_SUBDIR, ARG_NUM_EXECUTIONS, ARG_VERBOSE),
    ),
    ActionCommand(
        name="pause",
        help="Pause a DAG",
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_pause"),
        args=(ARG_DAG_ID, ARG_SUBDIR, ARG_VERBOSE),
    ),
    ActionCommand(
        name="unpause",
        help="Resume a paused DAG",
        func=lazy_load_command("airflow.cli.commands.dag_command.dag_unpause"),
        args=(ARG_DAG_ID, ARG_SUBDIR, ARG_VERBOSE),
    ),
    ActionCommand(
        name="trigger",
        help=(