test_customize_compiler_with_msvc_python: skip for cygwin #65

Job	Run time
test_cygwin (39, windows-latest)	3m 27s
collateral (diffcov)	1m 4s
ci_setuptools (3.10, ubuntu-latest)	3m 49s
collateral (docs)	35s
test (3.8, ubuntu-latest)	38s
test_msys2_mingw (mingw64, x86_64, gcc, g++)	2m 9s
test_msys2_mingw (mingw32, i686, gcc, g++)	2m 37s
test (3.8, macos-latest)	1m 11s
test_msys2_mingw (ucrt64, ucrt-x86_64, gcc, g++)	2m 13s
test (3.8, windows-latest)	2m 3s
test_msys2_mingw (clang64, clang-x86_64, clang, clang++)	2m 21s
test (3.12, ubuntu-latest)	45s
test (3.12, macos-latest)	51s
test (3.12, windows-latest)	1m 52s
test (3.9, ubuntu-latest)	42s
test (3.10, ubuntu-latest)	42s
test (3.11, ubuntu-latest)	42s
test (pypy3.10, ubuntu-latest)	1m 34s
check	4s
release	0s
	29m 19s

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