planner: fix index heuristic rule will prune out hint preferred tiflash path (#46102)

[ti-chi-bot]

This is an automated cherry-pick of #46102

What problem does this PR solve?

Issue Number: close #40146

Problem Summary:

What is changed and how it works?

After the logical plan tree is built, the access paths have been filled;
while in the pre-action of the physical optimization phase, the heuristic rule in datasource.DeriveStats will prune out the hint preferred tiflash read table path, causing can't find proper physical plan error

Check List

Tests

• 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

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

planner: fix index heuristic rule will prune out hint preferred tiflash path

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: time-and-fate, winoros

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-08-17 07:02:49.46060813 +0000 UTC m=+787334.009624117: ☑️ agreed by time-and-fate.
• 2023-08-17 07:13:37.826758618 +0000 UTC m=+787982.375774605: ☑️ agreed by winoros.

[codecov]

Codecov Report

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Additional details and impacted files

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