fix: Have sum operate on the passed dtype.

[flying-sheep]

Fixes #124

discovered by @quentinblampey in #116 (comment)

super strange: why is the cs{rc}_{matrix_array} result different than when using numpy?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.32%. Comparing base (49bdfac) to head (7b08275).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #125      +/-   ##
==========================================
- Coverage   98.32%   98.32%   -0.01%     
==========================================
  Files          17       17              
  Lines         419      418       -1     
==========================================
- Hits          412      411       -1     
  Misses          7        7              

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[codspeed-hq]

CodSpeed Performance Report

Merging #125 will not alter performance

_{Comparing pa/fix-precision (7b08275) with main (49bdfac)}

Summary

✅ 160 untouched

[ilan-gold]

Do you really want me to review this @flying-sheep ? The tests seem quite broken?

[flying-sheep]

We talked about how to handle it already, so I think we’re good for now!

scipy/scipy#23768

[flying-sheep]

now it’s ready!