Revert "Activate unschedulable pods only if the node became more schedulable"

[bsalamat]

We have seen high CPU usage and increased latency after the PR that we are reverting here got merged:
Reverts #70366

I was a bit worried when we started the PR, because our node updates are frequent and we spent a significant amount of time to compare node objects. For now, I am reverting the PR. We will try to find ways to optimize the algorithm further.
The main reason that we worked on the original PR was to reduce the number of times the scheduler retries pods after receiving node updates. However, in situations where there is no unschedulable pods (which is the case in our scalability tests), we only spend time comparing node object without getting anything in return. In those cases, we could have bypassed all the checks as the scheduler wouldn't have found any pods to retry.

ref/ #70708
/sig scheduling

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[k8s-ci-robot]

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[Huang-Wei]

/lgtm

Thanks @bsalamat.

[Huang-Wei]

/lgtm

Thanks @bsalamat.

[AishSundar]

/kind bug
/priority important-soon
/milestone v1.13

[AishSundar]

/release-note-none