Add Utah homeowner/renter property tax relief

[daphnehanse11]

Summary

• Adds Utah Homeowner's/Renter's Relief eligibility using the current age, surviving-spouse, income, and rent/property-tax rules.
• Adds the 2025 household-income schedule used for 2026 applications, including renter percentage rates and maximum homeowner/renter amounts.
• Adds focused eligibility and amount tests.

Closes #8182.

Note: this PR models the core homeowner credit and renter credit schedule. It does not separately model the homeowner add-on equal to tax on 20 percent of home fair market value because PE-US does not currently have the Utah-specific property tax mechanics needed to price that add-on separately.

Tests

• /Users/daphnehansell/Documents/GitHub/policyengine-us/.venv/bin/python policyengine_us/tests/test_batched.py policyengine_us/tests/policy/baseline/gov/states/ut/tax/property/homeowner_renter_relief --batches 1
• /Users/daphnehansell/Documents/GitHub/policyengine-us/.venv/bin/ruff check policyengine_us/variables/gov/states/ut/tax/property/homeowner_renter_relief
• /Users/daphnehansell/Documents/GitHub/policyengine-us/.venv/bin/python -m pytest policyengine_us/tests/test_parameter_files.py policyengine_us/tests/test_system_import.py

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (8cb60e7) to head (e5d0248).
⚠️ Report is 66 commits behind head on main.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files            3         4    +1     
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+ Hits            63        69    +6     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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[MaxGhenis]

I reviewed the latest head and checked the existing PR comments/reviews. There are no prior human review comments on this PR, but I found two blockers against the Utah statute/form.

1. policyengine_us/variables/gov/states/ut/tax/property/homeowner_renter_relief/ut_homeowner_renter_relief_eligible.py:24 and policyengine_us/variables/gov/states/ut/tax/property/homeowner_renter_relief/ut_homeowner_renter_relief.py:20 use the claimant tax unit's adjusted_gross_income as the program income. Utah Code 59-2a-101 defines household income as income received by all members of the claimant's household, with specific exclusions, and TC-90CB has a household income worksheet for cases where more than one household member received income. In a two-tax-unit household, this PR ignores the other adult's income for both eligibility and the amount schedule. I reproduced this with a temporary YAML case where an age-eligible renter with $10k income lived with another adult tax unit earning $60k; the model still returned the claimant eligible.

2. The eligibility formula omits the dependent-claimant exclusion. Utah Code 59-2a-205(4) for renter credits and 59-2a-305(2)(a) for homeowner credits disallow the credit when the individual is claimed as another person's exemption/dependent, and TC-90CB asks whether the claimant cannot be claimed on someone else's return. The repo already has claimed_as_dependent_on_another_return / head_is_dependent_elsewhere style signals. I reproduced this with a temporary YAML case where a filer with claimed_as_dependent_on_another_return: true still returned ut_homeowner_renter_relief_eligible: true.

The rent-plus-property-tax case looks defensible: Utah Code 59-2a-202 and 59-2a-302 explicitly allow a claimant who meets both parts to claim a renter credit, homeowner credit, or both. The fixes above should be covered with regression tests before merge.