planner: fix a panic during column pruning (#47883)

[ti-chi-bot]

This is an automated cherry-pick of #47883

What problem does this PR solve?

Issue Number: close #47331

Problem Summary:

What is changed and how it works?

Through my investigation, I identified several key points:

1. The panic occurs during DeriveStats: p.StatsInfo().ColNDVs[selfSchema.Columns[i].UniqueID] = childProfile.RowCount.
2. There's a discrepancy in the number of expressions and schema columns: the plan has 8 expressions but only 7 columns in the schema.
3. The logic plan causing the panic is a projection (ID 25), generated by the joinReOrderSolver.
4. Post-debugging, I noted that the schema undergoes changes after the LogicalProjection.PruneColumns process.
5. On further debugging the PruneColumns function individually, I discovered that the schema of projection#25 is affected even before it's reached in the process.
6. This led me to suspect a memory issue. Notably, projection#18 and projection#25 appear to share the same schema memory address (0x14006b557c0).
7. Consequently, when a column is pruned from projection#18, projection#25 becomes corrupted, leading to a mismatch between expressions and columns.

So I cloned that schema and made sure we didn't have this kind of problem anymore.

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.

Fix a panic issue during column pruning

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idc-jenkins-ci-tidb/check_dev	7add326	link	true	/test check-dev
idc-jenkins-ci-tidb/unit-test	7add326	link	true	/test unit-test

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