Show ruff format diff in CI (#178)

Author: NiklasRosenstein

.github/workflows/publish-pypi.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Ruff check
         run: uv run ruff check
       - name: Ruff format
-        run: uv run ruff format --check
+        run: uv run ruff format --check --diff
 
   build-n-publish:
     name: Build and publish Python distributions to PyPI