util: change log level to debug calculating stale read ts (#47309)

[ti-chi-bot]

This is an automated cherry-pick of #47309

What problem does this PR solve?

Issue Number: close #47308

Problem Summary:
Change the log level to debug to reduce log numbers.

What is changed and how it works?

Check List

Tests

• Unit test

Side effects

Documentation

Release note

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

None

[ti-chi-bot]

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: crazycs520, ekexium

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-10-08 08:18:52.387223164 +0000 UTC m=+953929.974333310: ☑️ agreed by crazycs520.
• 2023-10-08 08:21:36.861607353 +0000 UTC m=+954094.448717493: ☑️ agreed by ekexium.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-6.5@62a0305). Click here to learn what that means.
The diff coverage is n/a.

Additional details and impacted files

@@               Coverage Diff                @@
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  Misses                 ?      74994           
  Partials               ?      16400           

[cfzjywxk]

/merge

[ti-chi-bot]

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