Update GitHub Actions workflow to use Node.js 20

.github/workflows/release.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          python -m pip install build twine sphinx cibuildwheel
+          python -m pip install build twine sphinx cibuildwheel sphinx_rtd_theme
           # pip install -r requirements.txt