crypto: Bump blst to 0.3.12

[vapourismo]

Improves RISC-V compatibility.

[emturner]

looks good to me! Though might need to bump rust version and/or change to cargo check --locked in the ci job

[vapourismo]

I had to bump curve25519-dalek to 4.1.3 but that one runs into unstable feature use errors in CI. The crate's MSRV is 1.60 and CI runs 1.64, I think 🤔

[vapourismo]

I had to bump curve25519-dalek to 4.1.3 but that one runs into unstable feature use errors in CI. The crate's MSRV is 1.60 and CI runs 1.64, I think 🤔

The issue is actually that stdsimd no longer exists it appears. Maybe upgrading Rust version will magically fix it 🗡️