rebase Scout shards to BF16-direct + F64x8 SIMD pipeline #70

Job	Run time
native-backend/stable	47s
nostd/thumbv6m-none-eabi/stable	24s
cargo-careful	37s
cross_test/s390x-unknown-linux-gnu/stable	1m 30s
cross_test/i686-unknown-linux-gnu/stable	1m 28s
miri	31s
format/stable	22s
docs/nightly	41s
Pass MSRV values to other jobs	2s
clippy/stable	26s
blas-msrv	56s
tests/beta	1m 31s
tests/stable	1m 23s
tests/1.64.0	1m 20s
conclusion	0s
	11m 58s

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