Change default value of tidb_enable_clustered_index back to INT_ONLY

[tangenta]

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[REVIEW NOTIFICATION]

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• Oreoxmt
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[Oreoxmt]

LGTM

[shichun-0415]

LGTM

[shichun-0415]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 9bc50fd

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #11639.

[benmaoer]

LGTM

[lifeijie6]

这个参数从on改回int_only的依据是什么。发现了性能或者什么问题吗？

[tangenta]

@lifeijie6 是因为 TiDB 的 PR 实际没有生效而文档的 PR 先合了，不是性能问题。从 int_only 到 on 改动最终会在 v6.4.0 发布。