### 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.
action="store_true",
)
ARG_DEFAULTS = Arg(
    ("-a", "--defaults"),
    help="Show only defaults - do not include local configuration, sources,"
    " includes descriptions, examples, variables. Comment out everything.",
    action="store_true",
)
ARG_VERBOSE = Arg(("-v", "--verbose"), help="Make logging output more verbose", action="store_true")
ARG_LOCAL = Arg(("-l", "--local"), help="Run the task using the LocalExecutor", action="store_true")
ARG_DONOT_PICKLE = Arg(
    ("-x", "--donot-pickle"),
    help=(
        "Do not attempt to pickle the DAG object to send over "
        "to the workers, just tell the workers to run their version "
        "of the code"
    ),
    action="store_true",
)
ARG_BF_IGNORE_DEPENDENCIES = Arg(
    ("-i", "--ignore-dependencies"),
    help=(
        "Skip upstream tasks, run only the tasks "
        "matching the regexp. Only works in conjunction "
        "with task_regex"
    ),
    action="store_true",
)
ARG_BF_IGNORE_FIRST_DEPENDS_ON_PAST = Arg(
    ("-I", "--ignore-first-depends-on-past"),