ticdc: Fix sql case error

[hongyunyan]

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• This PR is translated from: ticdc: Fix sql case error docs-cn#17495
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• Delete files
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-06-04 06:31:53.229241334 +0000 UTC m=+3362866.986376905: ☑️ agreed by qiancai.

[qiancai]

/approve

[ti-chi-bot]

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #17740.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #17741.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #17742.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #17743.