fix: Soundness when loading Parquet string statistics

[coastalwhite]

Fixes #20533.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.97%. Comparing base (f104170) to head (eba9a18).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #20585      +/-   ##
==========================================
- Coverage   78.98%   78.97%   -0.01%     
==========================================
  Files        1564     1564              
  Lines      220765   220771       +6     
  Branches     2504     2504              
==========================================
- Hits       174368   174364       -4     
- Misses      45823    45833      +10     
  Partials      574      574              

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