Fix the fail start of tiflash because of the zero division when getting cpu number (#9602)

[ti-chi-bot]

This is an automated cherry-pick of #9602

What problem does this PR solve?

Issue Number: close #9212

Problem Summary:

What is changed and how it works?

Check List

Tests

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

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

Fix the that fail to start tiflash because of the zero division when getting cpu number

[ti-chi-bot[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Lloyd-Pottiger, xzhangxian1008

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/pingcap/tiflash/blob/release-8.5/OWNERS)~~ [Lloyd-Pottiger] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[ti-chi-bot[bot]]

[LGTM Timeline notifier]

Timeline:

• 2024-11-15 09:39:49.780473534 +0000 UTC m=+608351.971342527: :ballot_box_with_check: agreed by xzhangxian1008.
• 2024-11-15 09:40:11.581467089 +0000 UTC m=+608373.772336084: :ballot_box_with_check: agreed by Lloyd-Pottiger.