Update release.yml

Author: philippeller

.github/workflows/release.yml

@@ -27,6 +27,6 @@ jobs:
           pip install .
       - name: Build package
         run: |
-          python -m build
+          python -m build --sdist
       - name: Publish package distributions to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1