Update policyengine dependency constraint

[anth-volk]

Fixes #3381

Summary

• Updated the policyengine dependency constraint to >=0.12.0,<1.
• Added a changelog fragment.

Checks

• make format
• ruff format --check .
• ruff check . (fails on existing repo-wide lint issues; first example: gcp/export.py F841)

[anth-volk]

We may not explicitly need to merge this to get the API running off newest version of PyPI <1. May instead just re-deploy API once PyPI is updated correctly.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.20%. Comparing base (2f4cf80) to head (bcc6988).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3382   +/-   ##
=======================================
  Coverage   72.20%   72.20%           
=======================================
  Files          56       56           
  Lines        2425     2425           
  Branches      423      423           
=======================================
  Hits         1751     1751           
  Misses        595      595           
  Partials       79       79           

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