Update PolicyEngine package versions

[anth-volk]

Summary

• Upgrade policyengine_us from 1.634.9 to 1.653.3.
• Upgrade policyengine_uk from 2.78.0 to 2.88.0.
• Remove the <3.24.0 upper bound from policyengine_core, leaving >=3.23.5.
• Add a generated uv.lock; the resolver currently selects policyengine-core==3.25.3.
• Add the required changelog fragment.

Validation

• uv lock
• uv lock --check
• uv run --python 3.12 python -c "import importlib.metadata as m; print('policyengine-us', m.version('policyengine-us')); print('policyengine-uk', m.version('policyengine-uk')); print('policyengine-core', m.version('policyengine-core'))"
• git diff --check

Notes

• A targeted pytest run against unit tests could not be completed locally because importing tests/unit/conftest.py initializes a real Cloud SQL connection before the SQLite override applies; with a dummy DB password it failed with MySQL access denied.
• A broad ruff check also reports existing repository lint violations unrelated to this PR.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.66%. Comparing base (6597d52) to head (1690e20).
⚠️ Report is 8 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3529      +/-   ##
==========================================
- Coverage   76.68%   76.66%   -0.02%     
==========================================
  Files          63       63              
  Lines        3444     3446       +2     
  Branches      620      621       +1     
==========================================
+ Hits         2641     2642       +1     
  Misses        629      629              
- Partials      174      175       +1     

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