This is an automated cherry-pick of #18040

What is changed and how it works?

Issue Number: Close #18107, Ref #18042

This PR mainly contains the following parts for optimization on scaling, used to mitigate the impacts, introduced by unnecessary ingesting sst files:

• Directly clearing stale ranges by DeleteByKeys during the balancing regions process.
• Do not clear data of offline stores during the scale-in process, as this data will be automatically cleared when the corresponding node goes offline.

What's Changed:

Optimizing the processing of clearing stale-ranges by DeleteByKeys, rather than ingesting.

This optimization is used to mitigate the impacts, introduced by unnecessary ingesting sst
files on latency when scaling.

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Taking the grpc messages duration in TiKV metrics panel as examples, positive performance feedbacks on reducing the long-tail latency can be reviewed from the following comparison results:

Commit	Comparisons on grpc messages duration
master
This PR

Meanwhile, the following E2E long-tail reduction also proves that this PR makes positive improvements effects:

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Release note

Optimizing the processing of clearing stale-ranges by DeleteByKeys to mitigate the impacts
on latency.