Update rand requirement from =0.8.5 to =0.9.0

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@0.8.5...0.9.0)

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

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

Cargo.toml

@@ -30,7 +30,7 @@ thiserror = "1.0"
 bitflags = "2"
 
 [dev-dependencies]
-rand = "=0.8.5"
+rand = "=0.9.0"
 trybuild = "1.0"
 clingo-derive = { version = "=0.2.0" }
 test-case = "3"