Update protox requirement from 0.5.0 to 0.6.0

Updates the requirements on [protox](https://github.com/andrewhickman/protox) to permit the latest version.
- [Changelog](https://github.com/andrewhickman/protox/blob/main/CHANGELOG.md)
- [Commits](andrewhickman/protox@0.5.0...0.6.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

wkt-types/Cargo.toml

@@ -36,4 +36,4 @@ prost-build = "0.12.1"
 prost-wkt-build = { version = "0.5.1", path = "../wkt-build" }
 regex = "1"
 protobuf-src = { version = "1.1.0", optional = true }
-protox = { version = "0.5.0", optional = true }
+protox = { version = "0.6.0", optional = true }