tests

WIP: Fix most mypy issues #1356

Job	Run time
test_cygwin (39, windows-latest)	7m 54s
test (3.9, ubuntu-latest)	55s
test (3.9, macos-latest)	1m 8s
ci_setuptools (3.10, ubuntu-latest)	4m 35s
test (3.9, windows-latest)	54s
test_msys2_mingw (mingw64, x86_64, gcc, g++)	1m 46s
test (3.13, ubuntu-latest)	1m 7s
test_msys2_mingw (mingw32, i686, gcc, g++)	1m 57s
collateral (diffcov)	1m 14s
test (3.13, macos-latest)	1m 16s
collateral (docs)	33s
test (3.13, windows-latest)	52s
test_msys2_mingw (ucrt64, ucrt-x86_64, gcc, g++)	1m 47s
test_msvc_python_mingw	2m 43s
test (3.10, ubuntu-latest)	57s
test_msys2_mingw (clang64, clang-x86_64, clang, clang++)	1m 44s
test (3.11, ubuntu-latest)	52s
test (3.12, ubuntu-latest)	54s
test (3.14, ubuntu-latest)	57s
test (pypy3.10, ubuntu-latest)	1m 6s
check	1s
release	0s
	35m 12s

Provide feedback