### 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_CONN_EXPORT = Arg(
    ("file",),
    help="Output file path for exporting the connections",
    type=argparse.FileType("w", encoding="UTF-8"),
)
ARG_CONN_EXPORT_FORMAT = Arg(
    ("--format",),
    help="Deprecated -- use `--file-format` instead. File format to use for the export.",
    type=str,
    choices=["json", "yaml", "env"],
)
ARG_CONN_EXPORT_FILE_FORMAT = Arg(
    ("--file-format",), help="File format for the export", type=str, choices=["json", "yaml", "env"]
)
ARG_CONN_SERIALIZATION_FORMAT = Arg(
    ("--serialization-format",),
    help="When exporting as `.env` format, defines how connections should be serialized. Default is `uri`.",
    type=string_lower_type,
    choices=["json", "uri"],
)
ARG_CONN_IMPORT = Arg(("file",), help="Import connections from a file")
ARG_CONN_OVERWRITE = Arg(
    ("--overwrite",),
    help="Overwrite existing entries if a conflict occurs",
    required=False,
    action="store_true",
)
ARG_PROVIDER_NAME = Arg(
    ("provider_name",), help="Provider name, required to get provider information", type=str