message: Improve efficiency of `WorkQueue::to_stream`
diff: @@ -160,12 +160,9 @@ impl<T> WorkQueue<T> {
  /// Creates a streaming consumer of the work queue.
  #[inline]
  pub fn to_stream(self: Arc<Self>) -> impl Stream<Item = JobHandle<T>> {
  - stream::unfold((), move |_| {
  - let local_ref = self.clone();
  - async move {
  - let next = local_ref.next_job().await;
  - next.map(|handle| (handle, ()))
  - }
  + stream::unfold(self, |work_queue| async move {
  + let next = work_queue.next_job().await;
  + next.map(|handle| (handle, work_queue))
  })
  }
  