Fix gh-pages deployment

poetry install was not called, thus sphinx was not present

Author: schaefi

.github/workflows/ci-publish-pages.yml

@@ -25,6 +25,7 @@ jobs:
         python -m pip install poetry
     - name: Render
       run: |
+        poetry install --all-extras
         poetry run sphinx-build doc/source doc/build
     - name: Deploy
       uses: peaceiris/actions-gh-pages@v3