### 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="Configure pool",
        func=lazy_load_command("airflow.cli.commands.pool_command.pool_set"),
        args=(
            ARG_POOL_NAME,
            ARG_POOL_SLOTS,
            ARG_POOL_DESCRIPTION,
            ARG_POOL_INCLUDE_DEFERRED,
            ARG_OUTPUT,
            ARG_VERBOSE,
        ),
    ),
    ActionCommand(
        name="delete",
        help="Delete pool",
        func=lazy_load_command("airflow.cli.commands.pool_command.pool_delete"),
        args=(ARG_POOL_NAME, ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(
        name="import",
        help="Import pools",
        func=lazy_load_command("airflow.cli.commands.pool_command.pool_import"),
        args=(ARG_POOL_IMPORT, ARG_VERBOSE),
    ),
    ActionCommand(
        name="export",
        help="Export all pools",
        func=lazy_load_command("airflow.cli.commands.pool_command.pool_export"),
        args=(ARG_POOL_EXPORT, ARG_VERBOSE),
    ),
)