Bumps [sha2](https://github.com/RustCrypto/hashes) from 0.8.0 to 0.8.1. - [Release notes](https://github.com/RustCrypto/hashes/releases) - [Commits](https://github.com/RustCrypto/hashes/compare/sha2-v0.8.0...sha2-v0.8.1) Signed-off-by: dependabot-preview[bot] <support@dependabot.com>