statistics: handle the prune mode correctly in the refresher

[Rustin170506]

What problem does this PR solve?

Issue Number: close #57168

Problem Summary:

What changed and how does it work?

Cherry-pick of #57096
Cherry-pick of #57113

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

Attention: Patch coverage is 76.08696% with 11 lines in your changes missing coverage. Please review.

Please upload report for BASE (release-8.5@5518942). Learn more about missing BASE report.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-8.5     #57167   +/-   ##
================================================
  Coverage               ?   56.3266%           
================================================
  Files                  ?       1778           
  Lines                  ?     635000           
  Branches               ?          0           
================================================
  Hits                   ?     357674           
  Misses                 ?     253154           
  Partials               ?      24172           

Flag	Coverage Δ
integration	37.1615% <10.8695%> (?)
unit	72.5102% <76.0869%> (?)

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

Components	Coverage Δ
dumpling	52.9478% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	52.6484% <0.0000%> (?)

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[Rustin170506]

prefer #57169