Mypy couldn't infer type of thing

[KotlinIsland]

#356 (comment)

When UNSAFE_VARIANCE was only annotated with Final mypy couldn't determine it's type in the "Test suite with X, mypyc-compiled" jobs.

https://github.com/KotlinIsland/basedmypy/runs/7428344970?check_suite_focus=true

pip install -r test-requirements.txt
CC=clang MYPYC_OPT_LEVEL=0 python3 setup.py --use-mypyc build_ext --inplace

...

Successfully installed ast-decompiler-0.4.0 attrs-21.4.0 basedtyping-0.0.1 coverage-6.4.2 execnet-1.9.0 flake8-3.9.2 flake8-bugbear-22.3.20 flake8-pyi-22.5.1 iniconfig-1.1.1 lxml-4.9.1 mccabe-0.6.1 mypy_extensions-0.4.3 psutil-5.9.1 pycodestyle-2.7.0 pyflakes-2.3.1 pytest-7.1.2 pytest-cov-2.12.1 pytest-forked-1.4.0 pytest-xdist-2.5.0 tomli-2.0.1 typed_ast-1.5.4 types-typed-ast-1.5.7
mypy/message_registry.py:94: error: Cannot determine type of "UNSAFE_VARIANCE"
mypy/message_registry.py:99: error: Cannot determine type of "UNSAFE_VARIANCE"