fix sha256 napkin math numbers

[thundergolfer]

The sha256 performance numbers are too low. 1GiB/s throughput and ~100ns latency on 64b is achievable with just a bump in the package version, at least on my box :)

The benchmark uses 64b as its per-iteration chunk size, and this underestimates throughput (559MiB/s). At larger chunk sizes 1-1.5 GiB/s is achievable.

Matching tests with regex: hash_sha256

Executing hash_sha256..

[Sha256 <64 B>] Iterations in 5017 miliseconds, no overhead: 46,018,765
[Sha256 <64 B>] Iterations / second: 9,172,566
[Sha256 <64 B>] Bytes handled per iteration: 64 bytes
[Sha256 <64 B>] Total bytes processed: 2.743 GiB
[Sha256 <64 B>] Throughput: 559.849 MiB/s
[Sha256 <64 B>] Avg single iteration: 109 ns
[Sha256 <64 B>] Avg single iteration cycles: 0.00
[Sha256 <64 B>] Time to process 1 MiB: 1786 μs
[Sha256 <64 B>] Time to process 1 GiB: 1829 ms
[Sha256 <64 B>] Time to process 1 TiB: 31.22 min

I ran this on m6i.12xlarge running Ubuntu 20.04, but I generally find that 1GiB/s is the most accurate 'round number' for how fast sha256 is across our worker fleert.

[sirupsen]

@thundergolfer thank you 🙏🏻

I should re-run on a more recent x86 CPU, bet a lot of these are better now