metrics: fix wrong value in the sync load QPS

[hawkingrei]

What problem does this PR solve?

Issue Number: close #53558

Problem Summary:

What changed and how does it work?

Sync load's QPS in the grafana should be integer.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

before

after

• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.5428%. Comparing base (45318da) to head (f47c46c).
Report is 3 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #53559        +/-   ##
================================================
+ Coverage   72.5218%   74.5428%   +2.0209%     
================================================
  Files          1505       1505                
  Lines        430498     431222       +724     
================================================
+ Hits         312205     321445      +9240     
+ Misses        99118      89841      -9277     
- Partials      19175      19936       +761     

Flag	Coverage Δ
integration	49.2651% <ø> (?)
unit	71.3318% <ø> (-0.1772%)	⬇️

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

Components	Coverage Δ
dumpling	53.9957% <ø> (ø)
parser	∅ <ø> (∅)
br	50.4164% <ø> (+8.9920%)	⬆️

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AilinKid, qw4990

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• OWNERS [AilinKid,qw4990]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-27 04:46:56.744063694 +0000 UTC m=+2665370.501199267: ☑️ agreed by AilinKid.
• 2024-05-27 06:22:02.480458177 +0000 UTC m=+2671076.237593750: ☑️ agreed by qw4990.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #53569.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #53570.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #53571.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #53572.