Rust

clean up macro `impl_bytesn_repr` and remove export #6409

Job	Run time
cargo-deny (advisories)	40s
migration-docs	13s
setup	3s
check-git-rev-deps	5s
semver-checks	4m 26s
docs	3m 13s
readme	35s
expand-test-wasms	3m 44s
build-fuzz	43s
cargo-deny (bans licenses sources)	34s
fmt	6s
publish-dry-run	0s
build (latest, ubuntu-latest, x86_64-unknown-linux-gnu)	3m 49s
build (msrv, ubuntu-latest, x86_64-unknown-linux-gnu)	3m 55s
test	1s
complete	4s
	22m 11s

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