Automatic merge from submit-queue
dedup workqueue requeuing
Updates `workqueue.AddAfter` to only perform the add for the earliest requested requeue operation. An earlier time inserts in the earlier slot and removes the old one. A later time is ignored.
When using this conjunction with an `AddRateLimited` method, you get charged for the additional retry even though you're only queue once.
This keeps requeues from multiplying for every add.
@liggitt