log:degrade some log (#9620)

[ti-chi-bot]

This is an automated cherry-pick of #9620

What problem does this PR solve?

Issue Number: Ref #9370

What is changed and how does it work?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Code changes

• Has the configuration change
• Has HTTP API interfaces changed (Don't forget to add the declarative for the new API)
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• PR to update pingcap/tiup:
• Need to cherry-pick to the release branch

Release note

None.

[ti-chi-bot]

This cherry pick PR is for a release branch and has not yet been approved by triage owners.
Adding the do-not-merge/cherry-pick-not-approved label.

To merge this cherry pick:

1. It must be approved by the approvers firstly.
2. AFTER it has been approved by approvers, please wait for the cherry-pick merging approval from triage owners.

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 kubernetes-sigs/prow repository.

[bufferflies]

/ping @lhy1024 @okJiang

[bufferflies]

/ping @lhy1024

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bufferflies, okJiang

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:

• OWNERS [bufferflies]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-08-27 03:05:40.801864888 +0000 UTC m=+323032.679695832: ☑️ agreed by bufferflies.
• 2025-08-27 04:00:15.236585514 +0000 UTC m=+326307.114416468: ☑️ agreed by okJiang.