- Improved Node's QueueingHint in the `NodeAffinity` plugin by ignoring unrelated changes that keep pods unschedulable. ([#127444](https://github.com/kubernetes/kubernetes/pull/127444), [@dom4ha](https://github.com/dom4ha)) [SIG Scheduling and Testing]

  Previously, when unschedulable Pods are updated, the scheduler always put Pods back to activeQ/backoffQ. But, actually not all updates to Pods make Pods schedulable, especially considering many scheduling constraints nowadays are immutable.

- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active"...

- DRA: the explanation for why a pod which wasn't using ResourceClaims was unscheduleable included a useless "no new claims to deallocate" when it was unscheduleable for some other reasons. ([#129823](https://github.com/kubernetes/kubernetes/pull/129823), [@googs1025](https://github.com/googs1025)) [SIG Node and Scheduling]

- Removed the deprecated `--register-schedulable` command line argument from the kubelet. ([#122384](https://github.com/kubernetes/kubernetes/pull/122384), [@carlory](https://github.com/carlory)) [SIG Cloud Provider, Node and Scalability]