Expand Zip to up to 9 producers #607

Job	Run time
docs/nightly	23s
miri	10m 39s
Pass MSRV values to other jobs	4s
cargo-careful	2m 8s
cross_test/s390x-unknown-linux-gnu/stable	8m 54s
format/nightly	17s
nostd/thumbv6m-none-eabi/stable	15s
clippy/stable	22s
cross_test/i686-unknown-linux-gnu/stable	2m 0s
tests/beta	2m 35s
tests/nightly	3m 17s
tests/stable	2m 39s
tests/1.64.0	3m 25s
blas-msrv	44s
conclusion	0s
	37m 42s

Provide feedback