sink(ticdc): fix duplicated replace when batch-replace is disabled (#4502)

[ti-chi-bot]

This is an automated cherry-pick of #4502

What problem does this PR solve?

Issue Number: close #4501

What is changed and how it works?

Remove duplicated sqls.

Check List

Tests

• Unit test
• Integration test

Release note

Fix a bug that MySQL sink will generate duplicated replace SQL if `batch-replace-enable` is disabled.

[ti-chi-bot]

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[ti-chi-bot]

@ti-chi-bot: This cherry pick PR is for a release branch and has not yet been approved by release team.
Adding the do-not-merge/cherry-pick-not-approved label.

To merge this cherry pick, it must first be approved by the collaborators.

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[codecov-commenter]

Codecov Report

Merging #4503 (a0d93f7) into release-4.0 (753073a) will increase coverage by 8.1335%.
The diff coverage is 74.2237%.

@@                 Coverage Diff                 @@
##           release-4.0      #4503        +/-   ##
===================================================
+ Coverage      53.7661%   61.8996%   +8.1335%     
===================================================
  Files              153        162         +9     
  Lines            15958      16824       +866     
===================================================
+ Hits              8580      10414      +1834     
+ Misses            6475       5512       -963     
+ Partials           903        898         -5     

[VelocityLight]

This pull request is closed because it's related version has closed automatic cherry-picking.
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see:

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• https://book.prow.tidb.net/#/plugins/cherrypicker

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• https://internals.tidb.io/t/topic/785