Cannot build: unknown feature `stdsimd`

Building master with nightly gives:
```
error[E0635]: unknown feature `stdsimd`
  --> /home/charles/.cargo/registry/src/index.crates.io-6f17d22bba15001f/ahash-0.7.6/src/lib.rs:33:42
   |
33 | #![cfg_attr(feature = "stdsimd", feature(stdsimd))]
   |                                          ^^^^^^^
```

Running `cargo update` to update to the latest dependencies fixes the issue.

