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
• 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