planner: fix leading hint cannot take effect in UNION ALL statements (#50277)

[ti-chi-bot]

This is an automated cherry-pick of #50277

What problem does this PR solve?

Issue Number: close #50067

Problem Summary:

What changed and how does it work?

the root cause is that the PlanBuilder.tableHintInfo will be overwritten by push/pop in the buildSelect

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

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hawkingrei

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-01-12 09:08:38.277814184 +0000 UTC m=+607107.862067871: ☑️ agreed by hawkingrei.