executor: fix 2nd index dup check after insert ignore on dup update primary (#23814)

[ti-srebot]

cherry-pick #23814 to release-5.0
You can switch your code base to this Pull Request by using git-extras:

# In tidb repo:
git pr https://github.com/pingcap/tidb/pull/23826

After apply modifications, you can push your change to this PR via:

git push [email protected]:ti-srebot/tidb.git pr/23826:release-5.0-096281ec2f9a

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What problem does this PR solve?

Issue Number: close #23809

Problem Summary:

see more detail at

#23809 (comment)

What is changed and how it works?

What's Changed, How it Works:

remove old record if new record can added

Related changes

• Need to cherry-pick to the release branch 5.0 / 4.0?

Check List

Tests

• Unit test

Side effects

• n/a

Release note

• Fix insert ignore on duplicate may delete wrong record

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This change is 

[ti-srebot]

/run-all-tests

[ti-srebot]

@lysu you're already a collaborator in bot's repo.

[cfzjywxk]

/lgtm

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• cfzjywxk
• tangenta

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[coocood]

/lgtm

[lysu]

/merge

[ti-chi-bot]

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

Commit hash: fc8fe51