DOC: fix doctest output in transformations.py for newer NumPy

[Kd1880]

Fixes part of #3925

What was wrong

The doctest in decompose_matrix() in transformations.py had an
outdated expected output. Newer versions of NumPy return
np.float64(0.123) instead of 0.123.

What I changed

Updated the expected output in the docstring from 0.123
to np.float64(0.123).

Tests

Ran python -m sphinx -b doctest source/ _build/doctest —
all 160 doctests in transformations.py now pass.

AI Usage Declaration

AI tools (Claude by Anthropic) were used to help identify and
understand the fix. The actual code change was made manually
by me after understanding the issue.

[github-actions]

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.82%. Comparing base (54d37c2) to head (d0e2e54).
⚠️ Report is 4 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #5283   +/-   ##
========================================
  Coverage    93.82%   93.82%           
========================================
  Files          180      182    +2     
  Lines        22477    22483    +6     
  Branches      3191     3195    +4     
========================================
+ Hits         21089    21095    +6     
  Misses         925      925           
  Partials       463      463           

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