build only source distribution

Author: bleykauf

.github/workflows/publish.yml

@@ -20,7 +20,7 @@ jobs:
         python -m pip install --upgrade pip
         pip install build --user
     - name: Build binary wheel and a source tarball
-      run: python -m build
+      run: python -m build --sdist
     - name: Store the distribution packages
       uses: actions/upload-artifact@v3
       with: