Move compilers into their own package #1166

Job	Run time
collateral (diffcov)	59s
ci_setuptools (3.10, ubuntu-latest)	3m 55s
test_cygwin (39, windows-latest)	5m 57s
collateral (docs)	26s
test (3.8, ubuntu-latest)	38s
test (3.8, macos-latest)	1m 10s
test_msvc_python_mingw	3m 24s
test (3.8, windows-latest)	2m 24s
test_msys2_mingw (mingw64, x86_64, gcc, g++)	1m 37s
test (3.12, ubuntu-latest)	44s
test_msys2_mingw (mingw32, i686, gcc, g++)	2m 11s
test (3.12, macos-latest)	1m 5s
test_msys2_mingw (ucrt64, ucrt-x86_64, gcc, g++)	1m 40s
test (3.12, windows-latest)	1m 52s
test_msys2_mingw (clang64, clang-x86_64, clang, clang++)	1m 44s
test (3.9, ubuntu-latest)	41s
test (3.10, ubuntu-latest)	37s
test (3.11, ubuntu-latest)	51s
test (pypy3.10, ubuntu-latest)	1m 40s
check	1s
release	0s
	33m 36s

Provide feedback