Update ahash

[keith]

Otherwise the build fails with:

error[E0635]: unknown feature `stdsimd`
  --> ~/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/ahash-0.8.6/src/lib.rs:99:42
   |
99 | #![cfg_attr(feature = "stdsimd", feature(stdsimd))]
   |                                          ^^^^^^^

https://users.rust-lang.org/t/error-e0635-unknown-feature-stdsimd/106445