Update serialization

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 72.72727% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 88.76%. Comparing base (b034896) to head (90f1fed).

Files	Patch %	Lines
foamlib/_files/_serialization.py	71.87%	9 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #96 +/- ## ========================================== - Coverage 88.79% 88.76% -0.03% ========================================== Files 10 10 Lines 803 801 -2 ========================================== - Hits 713 711 -2 Misses 90 90 ```

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