dm: fix leader did not retire after delete the key

[GMHDBJD]

What problem does this PR solve?

Issue Number: close #11602

What is changed and how it works?

Check List

Tests

• Unit test

Questions

Will it cause performance regression or break compatibility?

Do you need to update user documentation, design documentation or monitoring documentation?

Release note

Fix leader did not retire after delete the key

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 57.6171%. Comparing base (45c831a) to head (88d0d0c).
Report is 53 commits behind head on master.

Additional details and impacted files

Components	Coverage Δ
cdc	61.4435% <ø> (+0.2113%)	⬆️
dm	51.0846% <100.0000%> (+0.0512%)	⬆️
engine	63.4444% <ø> (+0.0494%)	⬆️

Flag	Coverage Δ
unit	57.6171% <100.0000%> (+0.1399%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

@@               Coverage Diff                @@
##             master     #11604        +/-   ##
================================================
+ Coverage   57.4771%   57.6171%   +0.1399%     
================================================
  Files           851        851                
  Lines        126539     126872       +333     
================================================
+ Hits          72731      73100       +369     
+ Misses        48407      48373        -34     
+ Partials       5401       5399         -2     

[D3Hunter]

why change filemode?

[GMHDBJD]

Weird, I changed it back

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: D3Hunter, lance6716

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Needs approval from an approver in each of these files:

• dm/OWNERS [D3Hunter,lance6716]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-09-24 07:51:48.86383256 +0000 UTC m=+1552378.604256499: ☑️ agreed by lance6716.
• 2024-09-24 07:56:50.178334364 +0000 UTC m=+1552679.918758303: ☑️ agreed by D3Hunter.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #11625.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #11626.

[ti-chi-bot]

In response to a cherrypick label: new pull request could not be created: failed to create pull request against pingcap/tiflow#release-7.1 from head ti-chi-bot:cherry-pick-11604-to-release-7.1: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later. If you reach out to GitHub Support for help, please include the request ID ACA6:3F108B:1B752B6:33BCE2C:671F4640 and timestamp 2024-10-28 08:07:29 UTC.","documentation_url":"https://docs.github.com/rest/overview/rate-limits-for-the-rest-api#about-secondary-rate-limits","status":"403"}

[MimeLyc]

/cherry-pick release-7.1

[ti-chi-bot]

@MimeLyc: new pull request created to branch release-7.1: #11732.

In response to this:

/cherry-pick release-7.1

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #11858.