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] <support@github.com>

Cargo.toml

@@ -24,7 +24,7 @@ tracing = {version = "0.1", default-features = false, features = ["std"]}
 tokio-tungstenite = {version = "0.26", default-features = false}
 
 [dev-dependencies]
-rand = {version = "0.8", default-features = false, features = ["std", "std_rng"]}
+rand = {version = "0.9", default-features = false, features = ["std", "std_rng"]}
 serde = {version = "1.0", features = ["derive"]}
 test-log = {version = "0.2.8", default-features = false, features = ["trace"]}
 tokio = {version = "1.8", default-features = false, features = ["rt", "macros", "net", "test-util"]}