build(deps): update rand requirement from 0.8.0 to 0.9.1

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...0.8.5)

---
updated-dependencies:
- dependency-name: rand
  dependency-version: 0.8.5
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -27,7 +27,7 @@ members = [
 [workspace.dependencies]
 serde_json = "1.0.41"
 criterion = "0.6.0"
-rand = { version = "0.8.0", default-features = false }
+rand = { version = "0.9.1", default-features = false }
 hex-literal = "1.0.0"
 scale-info = { version = ">=1.0, <3", default-features = false }
 quickcheck = "1"