Update ron requirement from 0.8 to 0.12 (#1)

Updates the requirements on [ron](https://github.com/ron-rs/ron) to permit the latest version.
- [Release notes](https://github.com/ron-rs/ron/releases)
- [Changelog](https://github.com/ron-rs/ron/blob/master/CHANGELOG.md)
- [Commits](ron-rs/ron@v0.8.0...v0.12.0)

---
updated-dependencies:
- dependency-name: ron
  dependency-version: 0.12.0
  dependency-type: direct:production
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.toml

@@ -14,7 +14,7 @@ z3 = { version = "0.19", features = ["static-link-z3"] }
 # Serialization
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-ron = "0.8"
+ron = "0.12"
 
 # Steam integration
 steamworks = "0.12"