Bump Python wrapper version to 0.4.2

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mivertowski

crates/ringkernel-python/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "ringkernel"
-version = "0.4.0"
+version = "0.4.2"
 description = "GPU-native persistent actor model framework"
 readme = "README.md"
 license = { text = "MIT OR Apache-2.0" }