Function make_shutdown

crates/openshell-server/src/supervisor_session.rs:832–834

Returns a shutdown sender with its receiver immediately dropped. Tests that don't observe the shutdown signal can use this to satisfy the `register` signature without the receiver noise.

()

    /// that don't observe the shutdown signal can use this to satisfy the
    /// `register` signature without the receiver noise.
    fn make_shutdown() -> oneshot::Sender<()> {
        oneshot::channel::<()>().0
    }

    fn sandbox_record(id: &str, name: &str) -> Sandbox {
        Sandbox {