update gh doc action

.github/workflows/python-documentation.yml

@@ -20,15 +20,8 @@ jobs:
           python-version: "3.9"
       - name: Install dependencies
         run: |
-          pip install sphinx myst_parser
+          pip install sphinx myst_parser sphinx-rtd-theme
           pip install .
       - name: Sphinx build
         run: |
           sphinx-build docs docs/_build
-      - name: Deploy to GitHub Pages
-        uses: peaceiris/actions-gh-pages@v3
-        with:
-          publish_branch: gh-pages
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: docs/_build/
-          force_orphan: true