Replace JSON3.pretty with JSON3.write

[nhz2]

This avoids some bugs and performance issues in JSON3 and creates slightly smaller files.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.51%. Comparing base (699d526) to head (7608c29).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #66   +/-   ##
=======================================
  Coverage   95.51%   95.51%           
=======================================
  Files          11       11           
  Lines         580      580           
=======================================
  Hits          554      554           
  Misses         26       26           

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