Update rand requirement from 0.8 to 0.9

Updates the requirements on [rand](https://github.com/rust-random/rand) to permit the latest version.
- [Release notes](https://github.com/rust-random/rand/releases)
- [Changelog](https://github.com/rust-random/rand/blob/master/CHANGELOG.md)
- [Commits](rust-random/rand@0.8.0...0.9.0)

---
updated-dependencies:
- dependency-name: rand
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Cargo.toml

@@ -28,7 +28,7 @@ bincode = "1"
 criterion = "0.5"
 lazy_static = "1.4"
 proptest = "1.0"
-rand = "0.8"
+rand = "0.9"
 rand_chacha = "0.3"
 serde_json = "1.0"