[REFACTOR]: Remove repetitive code. Remove dead Python 3.8 code. Add …

[genedan]

Summary of Changes

Remove repetitive code. Remove dead Python 3.8 code. Add missing unit tests.

Repetitive code would be variables like _DT64_DTYPE which then get assigned to something like DT64_DTYPE. Rewrite reset_option to remove copy-pasted code from initialization.

Related GitHub Issue(s)

Partially addresses #856
Closes #862

Additional Context for Reviewers

• I passed tests locally for both code (uv run pytest) and documentation changes (uv run jb build docs --builder=custom --custom-builder=doctest)

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Note

Medium Risk
DT64_DTYPE now stores .dtype.name instead of str(dtype), which could affect datetime casting in core triangle code if the string form differs from before; otherwise changes are mostly internal refactor and test infrastructure.

Overview
Refactors Options from class-level defaults into instance initialization, documents get_option / set_option / reset_option, and makes reset_option call __init__() instead of duplicating default assignments. DT64_DTYPE is now derived via .dtype.name (dropping module-level _DT64_DTYPE / _ULT_VAL), and __version__ always uses importlib.metadata (Python 3.8 importlib_metadata fallback removed).

conftest.py centralizes sample-triangle fixtures in _sample_fixture, yielding triangles with backend setup/teardown instead of repeating ARRAY_BACKEND logic per fixture.

test_utilities.py expands coverage for options defaults, get/set consistency, reset_option (with teardown), and deprecation warnings on array_backend / auto_sparse.

^{Reviewed by Cursor Bugbot for commit 70fe2a5. Bugbot is set up for automated code reviews on this repo. Configure here.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.16%. Comparing base (9e833f6) to head (70fe2a5).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #857      +/-   ##
==========================================
+ Coverage   86.94%   87.16%   +0.21%     
==========================================
  Files          86       86              
  Lines        4994     5047      +53     
  Branches      644      648       +4     
==========================================
+ Hits         4342     4399      +57     
+ Misses        462      457       -5     
- Partials      190      191       +1     

Flag	Coverage Δ
unittests	87.16% <100.00%> (+0.21%)	⬆️

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[genedan]

Updated to close #862 which was a bug I discovered while trying to write the tests.

[henrydingliu]

mostly clean-up of current code. i assume more enhancements will come through #860

[henrydingliu]

does it also address #863?

[genedan]

yeah