br: fix flaky test (#52573)

[ti-chi-bot]

This is an automated cherry-pick of #52573

What problem does this PR solve?

Issue Number: close #52547

Problem Summary:
the flaky test TestGetTSWithRetry takes too much time.

What changed and how does it work?

less retry

Check List

Tests

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

❗ No coverage uploaded for pull request base (release-8.1@9d3f10a). Click here to learn what that means.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-8.1     #52665   +/-   ##
================================================
  Coverage               ?   73.2899%           
================================================
  Files                  ?       1470           
  Lines                  ?     436315           
  Branches               ?          0           
================================================
  Hits                   ?     319775           
  Misses                 ?      97429           
  Partials               ?      19111           

Flag	Coverage Δ
unit	72.3186% <100.0000%> (?)

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

Components	Coverage Δ
dumpling	53.9957% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	41.0335% <0.0000%> (?)

[BornChanger]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: BornChanger, Leavrth

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• br/OWNERS [BornChanger,Leavrth]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-06 11:57:55.38103444 +0000 UTC m=+876829.138170013: ☑️ agreed by BornChanger.
• 2024-05-07 07:41:56.207240618 +0000 UTC m=+947869.964376191: ☑️ agreed by Leavrth.