Use `sha256-simd` instead of native Golang implementation

[Wondertan]

Having a computation speed-up through easy to integrate lib for such a widely used primitive is awesome.

[liamsi]

ref: https://github.com/lazyledger/lazyledger-core/pull/351

[rootulp]

Closing this as won't do b/c a goal of this repo is to minimize the diff between celestia-core and upstream cometBFT. Please re-open if this should still be considered.

[evan-forbes]

also fwiw the speed up between the standard library and simd should be significantly smaller after go 1.21