fix: align EXPLAIN output with actual partition pruning statistics

[dqhl76]

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Summary

After the pruning pipeline was implemented, the physical plan could only access lazy partition information without actual pruning statistics. As a temporary workaround, EXPLAIN statements were using the old pruning method prune_snapshot_blocks, which produced results that didn't accurately reflect the actual query execution behavior.

This PR fixes this inconsistency by making EXPLAIN statements execute the pruning pipeline, ensuring that the displayed execution plan and statistics match what actually happens during real query execution.

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[BohuTANG]

@dqhl76 This was closed without explanation. Could you clarify why?

[dqhl76]

Misoperation, I recently want to continue pushing this PR move.