fix: resolve mypy strict errors in models.py and code_utils.py #307

Job	Run time
check-linked-issue	3s
determine-changes / detect	8s
type-check	22s
unit-tests (ubuntu-latest, 3.14)	6m 16s
unit-tests (ubuntu-latest, 3.9)	8m 43s
e2e-python (async-optimization, end_to_end_test_async.py, 10)	2m 34s
prek / prek	36s
e2e-python (bubble-sort-pytest-nogit, end_to_end_test_bubblesort_pytest.py, 70, true)	4m 29s
unit-tests (ubuntu-latest, 3.13)	7m 33s
unit-tests (windows-latest, 3.13)	10m 28s
e2e-python (topological-sort, end_to_end_test_topological_sort_worktree.py, 5)	3m 10s
unit-tests (ubuntu-latest, 3.12)	6m 26s
e2e-python (futurehouse-structure, end_to_end_test_futurehouse.py, 5)	2m 45s
e2e-python (init-optimization, end_to_end_test_init_optimization.py, 10)	2m 20s
unit-tests (ubuntu-latest, 3.11)	7m 40s
e2e-python (coverage-e2e, end_to_end_test_coverage.py, black)	6m 12s
e2e-python (benchmark-bubble-sort, end_to_end_test_benchmark_sort.py, 5)	11m 49s
e2e-python (tracer-replay, end_to_end_test_tracer_replay.py, 10)	7m 6s
coverage	6m 43s
unit-tests (ubuntu-latest, 3.10)	7m 39s
e2e-python (bubble-sort-unittest, end_to_end_test_bubblesort_unittest.py, 40)	8m 58s
e2e-java	0s
e2e-js	0s
required checks passed	5s
	1h 52m 5s

Provide feedback