Cache env config #3642

Job	Run time
test 3.12 on ubuntu-latest	4m 42s
tox env type on ubuntu-latest	45s
test 3.12 on windows-latest	11m 13s
tox env type on windows-latest	1m 7s
test 3.12 on macos-latest	12m 46s
tox env dev on ubuntu-latest	37s
tox env dev on windows-latest	1m 27s
test 3.11 on ubuntu-latest	3m 23s
tox env docs on ubuntu-latest	2m 36s
test 3.11 on windows-latest	10m 55s
test 3.11 on macos-latest	10m 34s
tox env docs on windows-latest	5m 11s
test 3.10 on ubuntu-latest	3m 23s
tox env pkg_meta on ubuntu-latest	27s
test 3.10 on windows-latest	8m 7s
test 3.10 on macos-latest	10m 36s
test 3.9 on ubuntu-latest	3m 40s
test 3.9 on windows-latest	10m 36s
test 3.9 on macos-latest	10m 58s
test 3.8 on ubuntu-latest	3m 32s
test 3.8 on windows-latest	11m 59s
test 3.8 on macos-latest	7m 29s
	2h 16m 3s

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