Update digest requirement from 0.8 to 0.9

Updates the requirements on [digest](https://github.com/RustCrypto/traits) to permit the latest version.
- [Release notes](https://github.com/RustCrypto/traits/releases)
- [Commits](https://github.com/RustCrypto/traits/compare/digest-v0.8.0...digest-v0.9.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

lib/Cargo.toml

@@ -20,7 +20,7 @@ rand = "0.7"
 md-5 = "0.8"
 sha-1 = "0.8"
 sha2 = "0.8"
-digest = "0.8"
+digest = "0.9"
 regex = "1"
 oxilangtag = "0.1"
 oxiri = "0.1"