fix: merge if the number of lgtm is greater than the required number

[Rustin170506]

cc: pingcap/tidb#22860 (comment)

[github-actions]

🎊 PR Preview 282925b has been successfully built and deployed to https://ti-community-infra-tichi-preview-pr-367.surge.sh

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[codecov]

Codecov Report

Merging #367 (282925b) into master (9734e5d) will decrease coverage by 0.11%.
The diff coverage is 81.25%.

@@            Coverage Diff             @@
##           master     #367      +/-   ##
==========================================
- Coverage   83.82%   83.70%   -0.12%     
==========================================
  Files          14       14              
  Lines        1453     1516      +63     
==========================================
+ Hits         1218     1269      +51     
- Misses        139      144       +5     
- Partials       96      103       +7     

Flag	Coverage Δ
unittests	?

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Impacted Files	Coverage Δ
...nal/pkg/externalplugins/blunderbuss/blunderbuss.go	89.87% <80.85%> (-3.04%)	⬇️
internal/pkg/externalplugins/merge/merge.go	82.12% <100.00%> (ø)
internal/pkg/externalplugins/tars/tars.go	80.00% <0.00%> (+0.94%)	⬆️

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[Rustin170506]

/retest

[Rustin170506]

/test all

[Rustin170506]

/assign @Mini256

PTAL~ Thanks!

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• Mini256

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

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[Mini256]

/merge

[ti-chi-bot]

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

Commit hash: 282925b