Compilation error `use of unstable library feature 'stdsimd'`

There is a non-fixed version number in the https://github.com/ZcashFoundation/ed25519-zebra/blob/c39bd4364a03f4b8eb97c21b9aa6c9b357074280/Cargo.toml#L21 dependency that automatically updates curve25519-dalek from 4.1.1 to 4.1.2, introducing a breaking change (https://github.com/dalek-cryptography/curve25519-dalek/issues/622) where curve25519-dalek >= 4.1.2 will only work with the latest nightly to date, and polkadot-v1.6.0 will not work with the latest nightly. The Cargo.lock should not be regenerated until we fix the error upstream.