[Chapel Merge] Add missing import for python3

Branch: refs/heads/main
Revision: b3897ad
Author: aconsroe-hpe
Link: Add missing import for python3 by aconsroe-hpe · Pull Request #18739 · chapel-lang/chapel · GitHub
Log Message:

Merge pull request #18739 from aconsroe-hpe/reduce-python2

Add missing import for python3

reviewed by mppf

python3 removed the global reduce function, which is used in Fatal

Modified Files:
M util/test/sub_test.py

Compare: https://github.com/chapel-lang/chapel/compare/f49981376906...b3897ad6899d