fix: check all partitions for small files instead of the last only.

[youngsofun]

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Summary

Although ParquetFilesParts are always staying at the end of parts when do_read_partitions, but parts are reshuffled when redistribute_source_fragment, so let us check all of them.

Tests

• [ ] Unit Test
• [x] Logic Test
• [ ] Benchmark Test
• [ ] No Test - Explain why

Type of change

• [x] 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