fix: Use csr_matrix.getH() instead of H

[speller26]

csr_matrix.H has been removed in SciPy 1.14.0.

Issue #, if available:

Description of changes:

Testing done:

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (1fb70a7) to head (ed8a963). Report is 11 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #268 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 48 48 Lines 3763 3763 Branches 919 919 ========================================= Hits 3763 3763 ```

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