Update rkyv requirement from 0.7.43 to 0.8.3 #3478

Job	Run time
check-docs	13s
cross-tests (ubuntu-latest)	51s
cross-targets (x86_64-unknown-illumos)	48s
alternative_targets (ubuntu-latest, wasm32-unknown-emscripten)	9s
alternative_targets (ubuntu-latest, aarch64-apple-ios)	6s
features_check (ubuntu-latest)	6s
no_std (ubuntu-latest, thumbv6m-none-eabi)	9s
alternative_targets (ubuntu-latest, aarch64-linux-android)	10s
rust_msrv (ubuntu-latest)	2m 2s
no_std (ubuntu-latest, x86_64-fortanix-unknown-sgx)	12s
rust_versions (ubuntu-latest, stable)	24s
test_wasi (ubuntu-latest, wasm32-wasi)	8s
rust_versions (ubuntu-latest, beta)	27s
test_wasm (ubuntu-latest)	8s
timezones (ubuntu-latest, ACST-9:30)	7s
rust_versions (ubuntu-latest, nightly)	29s
timezones (ubuntu-latest, EST4)	1s
timezones (ubuntu-latest, UTC0)	1s
timezones (ubuntu-latest, Asia/Katmandu)	1s
timezones (macos-latest, ACST-9:30)	9s
timezones (macos-latest, EST4)	11s
timezones (macos-latest, UTC0)	9s
timezones (macos-latest, Asia/Katmandu)	9s
timezones (windows-latest, ACST-9:30)	1s
timezones (windows-latest, EST4)	1s
timezones (windows-latest, UTC0)	1s
timezones (windows-latest, Asia/Katmandu)	1s
	7m 14s

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