Bump actions/download-artifact from 3 to 4 #863

Job	Run time
Build x86_64 wheels on ubuntu-20.04	2m 22s
Build source distributions	12s
Build i686 wheels on ubuntu-20.04	2m 43s
Build manylinux_aarch64 wheels on ubuntu-20.04	10m 17s
Build musllinux_aarch64 wheels on ubuntu-20.04	10m 45s
Build manylinux_ppc64le wheels on ubuntu-20.04	9m 18s
Build musllinux_ppc64le wheels on ubuntu-20.04	10m 6s
Build manylinux_s390x wheels on ubuntu-20.04	8m 55s
Build musllinux_s390x wheels on ubuntu-20.04	9m 48s
Build AMD64 wheels on windows-2019	6m 41s
Build x86 wheels on windows-2019	7m 0s
Build x86_64 universal2 arm64 wheels on macos-11	10m 47s
Check dist	2s
Upload release to PyPI	0s
	1h 28m 56s

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