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>

Author: dependabot[bot]

plotly/Cargo.toml

@@ -40,7 +40,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 serde_repr = "0.1"
 serde_with = ">=2, <4"
-rand = "0.8"
+rand = "0.9"
 wasm-bindgen = { version = "0.2", optional = true }
 wasm-bindgen-futures = { version = "0.4", optional = true }