zerocopy: move repo to zerocopy 0.8 #1858

Job	Run time
build openhcl [aarch64-linux]	5m 25s
build artifacts [x64-linux]	6m 13s
build openhcl [x64-linux]	7m 56s
verify openhcl binary size [x64]	6m 31s
build and check docs [x64-windows]	9m 32s
build mdbook guide	1m 27s
clippy [windows], unit tests [x64-windows]	12m 21s
clippy [linux, macos], unit tests [x64-linux]	8m 14s
clippy [linux-musl, misc nostd], unit tests [x64-linux-musl]	7m 19s
unit tests [aarch64-windows]	7m 15s
build and check docs [x64-linux]	2m 44s
test flowey local backend	3m 11s
xtask fmt (linux)	2m 26s
build artifacts (not for VMM tests) [aarch64-windows]	5m 55s
build artifacts (for VMM tests) [aarch64-windows]	10m 31s
build artifacts (not for VMM tests) [x64-windows]	4m 46s
build artifacts (for VMM tests) [x64-windows]	10m 8s
build artifacts [aarch64-linux]	5m 27s
xtask fmt (windows)	7m 31s
run vmm-tests [aarch64-windows]	5m 31s
run vmm-tests [x64-windows-intel]	10m 58s
run vmm-tests [x64-windows-amd]	13m 26s
run vmm-tests [x64-linux]	3m 44s
openvmm checkin gates	5s
	2h 38m 36s

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