statistics: support global singleflight for sync load (#52796) (#53838)

[hawkingrei]

close #52797

What problem does this PR solve?

Issue Number: close #xxx

Problem Summary:

What changed and how does it work?

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

[YangKeao]

LGTM

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-07-01 07:44:41.339324659 +0000 UTC m=+1224007.824813484: ☑️ agreed by AilinKid.
• 2024-07-01 07:49:53.389987335 +0000 UTC m=+1224319.875476165: ☑️ agreed by YangKeao.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AilinKid, qw4990, YangKeao

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[hawkingrei]

/retest