### 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.
"""Display variable by a given name."""
    try:
        if args.default is None:
            var = Variable.get(args.key, deserialize_json=args.json)
            print(var)
        else:
            var = Variable.get(args.key, deserialize_json=args.json, default_var=args.default)
            print(var)
    except (ValueError, KeyError) as e:
        raise SystemExit(str(e).strip("'\""))
@cli_utils.action_cli
@providers_configuration_loaded
def variables_set(args):
    """Create new variable with a given name and value."""
    Variable.set(args.key, args.value, serialize_json=args.json)
    print(f"Variable {args.key} created")
@cli_utils.action_cli
@providers_configuration_loaded
def variables_delete(args):