Update z3 requirement from 0.12 to 0.19 (#4)

Updates the requirements on [z3](https://github.com/prove-rs/z3.rs) to permit the latest version.
- [Release notes](https://github.com/prove-rs/z3.rs/releases)
- [Changelog](https://github.com/prove-rs/z3.rs/blob/master/release-plz.toml)
- [Commits](https://github.com/prove-rs/z3.rs/commits/z3-v0.19.6)

---
updated-dependencies:
- dependency-name: z3
  dependency-version: 0.19.6
  dependency-type: direct:production
...

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Author: dependabot[bot]

Cargo.toml

@@ -9,7 +9,7 @@ bevy = { version = "0.13", features = ["dynamic_linking"] }
 bevy_egui = "0.38"
 
 # Verification
-z3 = { version = "0.12", features = ["static-link-z3"] }
+z3 = { version = "0.19", features = ["static-link-z3"] }
 
 # Serialization
 serde = { version = "1", features = ["derive"] }