* [Fix] Pandas 3 string type handling
* [ci] Temporarily remove WError because of scipy deprecation
* [Fix] Address edge cases in _deserialize_df
- Use pd.isna() instead of truthiness check for gzip null guard, fixing
incorrect behavior when null is np.nan (which is truthy in Python)
- Add bounds check to while loop to prevent IndexError when all non-null
values are empty strings converted to None by regex replace
* [Fix] Address edge cases in _deserialize_df and add string dtype tests
- Guard against IndexError on empty DataFrames and all-null columns
- Use is not None instead of pd.isna() for Obs objects in auto_gamma
- Add tests for string dtype columns (with/without None, CSV and SQL)
- Add test for empty DataFrame deserialization
* [Fix] Avoid skipping NA-to-None conversion and guard auto_gamma against None lists
- Replace continue with conditional to preserve NA-to-None conversion for all-null columns
- Guard auto_gamma list lambda against None values to prevent TypeError
- Add tests for all-empty-string columns and Obs lists with None + auto_gamma
* add option that the headers of an append-mode file can have different format
* add tests for irregular headers in append mode
* hotfix: fix bug in append start read implementation
* lint
* lint II
* [Fix] corrected expected_chisquare by adding the number of priors
* test/fits_test.py: dof and expected chisquare the same in uncorrelated fit w. prior to uncorrelated data
* [ci] Add python 3.14 runners for pytest workflow
* [ci] Deactivate -Werror option in pytest workflow to fix python 3.14
runner
* [ci] Run tests with Werror for all python versions but for 3.14