chore: Add set-version script and update all clients to 4.2.0

- Add scripts/set-version.sh to update version in all source files
- Add make set-version VERSION=X.Y.Z target
- Updated 11 files: VERSION, C, Python, Lua, Perl, Groovy, JS, Rust

clients/python/sync/setup.py

@@ -7,7 +7,7 @@ with open("README.md", "r", encoding="utf-8") as fh:
 
 setup(
     name="unsandbox",
-    version="1.0.0",
+    version="4.2.0",
     author="Unsandbox",
     description="Synchronous Python SDK for unsandbox.com code execution",
     long_description=long_description,