ep13b: Add cython back as a dev dependency for LSP

Author: obiwac

episode-13/poetry.lock

@@ -31,6 +31,7 @@ pyglm = "^2.7.1"
 [tool.poetry.group.dev.dependencies]
 ruff = "^0.5.5"
 pyright = "^1.1.374"
+cython = "^3.0.11"
 
 [tool.pyright]
 exclude = [".venv"]