fix: use sane mapreduce method

[AayushSabharwal]

No description provided.

[codecov-commenter]

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Codecov Report

❌ Patch coverage is 25.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.85%. Comparing base (99fbc36) to head (127efbc).
⚠️ Report is 65 commits behind head on master.

Files with missing lines	Patch %	Lines
src/array-lib.jl	25.00%	3 Missing ⚠️
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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1621      +/-   ##
==========================================
+ Coverage   80.08%   80.85%   +0.76%     
==========================================
  Files          53       56       +3     
  Lines        5358     5750     +392     
==========================================
+ Hits         4291     4649     +358     
- Misses       1067     1101      +34     

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