Drop PyPy 3.8 which seems to fail. #365

Job	Run time
pre-commit	35s
list	15s
test (tests-3.8)	1m 15s
test (tests-3.9)	1m 5s
test (tests-3.10)	1m 17s
test (tests-3.11)	1m 0s
test (tests-3.12)	1m 18s
test (tests-pypy3)	1m 50s
test (build)	1m 34s
windows (x64)	1m 46s
macos (x86_64)	2m 52s
musllinux (aarch64-unknown-linux-musl)	2m 20s
windows (x86)	1m 41s
manylinux (x86_64)	2m 37s
manylinux (x86)	3m 32s
macos (aarch64)	3m 33s
musllinux (i686-unknown-linux-musl)	2m 11s
manylinux (aarch64)	3m 2s
musllinux (x86_64-unknown-linux-musl)	2m 22s
manylinux (armv7)	3m 4s
manylinux (s390x)	3m 12s
manylinux (ppc64le)	3m 28s
Release	0s
	45m 49s

Provide feedback