fix the recommended range for region-split-size

[qiancai]

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[lilin90]

/lgtm

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[LGTM Timeline notifier]

Timeline:

• 2024-07-29 08:13:01.850867866 +0000 UTC m=+170698.130915935: ☑️ agreed by lilin90.

[qiancai]

/approve

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.0: #18188.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #18189.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.2: #18190.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.1: #18191.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #18192.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #18193.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #18194.