Add policyengine 4.4.3 bundle

[MaxGhenis]

Summary

• add bundle candidate and generated bundle for policyengine 4.4.3
• pin policyengine-us 1.690.7 with us-data 1.110.12 release manifest revision 3aac4505ec10d31efc1b3799a1e6458a15853ecc
• preserve unchanged UK data bundle metadata from the certified 4.4.2 bundle
• generate py313 constraints and pylock files for all/us/uk profiles

Verification

• uv run pytest -q
• uv run python scripts/validate_models.py
• uv run python scripts/validate_schemas.py
• uv run python scripts/validate_bundle.py bundles/4.4.3 --skip-data-verification
• targeted US data verification: release manifest sha256 9f47991b0bb7150c5f65b3b3fa9a11949b03162f047721960dcff46bbaee6536; enhanced_cps_2024.h5 sha256 58a6639f7511b8d804701417e2647f0c3a77f51a3d90441037eaf004b1f00761 and size 109844730 matched the manifest

Data verification was skipped in the bundle validator because the full validator downloads/hashes every certified artifact for every profile and the UK data release is private in this local environment. The US default data artifact was separately hash-verified; UK metadata is unchanged from 4.4.2.