Remove sha2 dependency

[mans0954]

Remove sha2 dependency - it doesn't appear to be referenced anywhere?

cargo remove sha2
cargo remove --manifest-path=src/elan-dist/Cargo.toml sha2
cargo remove --manifest-path=src/elan-utils/Cargo.toml sha2

[mans0954]

Although I was expecting it to be used to checksum downloaded files?

[Kha]

Thanks. This was likely used in rustup with the Rust release server but lost in our simpler GitHub Releases backend.