Restore custom Sphinx installation step with specific version in build workflow

Author: Revisto

.github/workflows/build-and-deploy.yml

@@ -36,9 +36,9 @@ jobs:
         run: make venv
         working-directory: ./Doc
 
-      # - name: Install custom Sphinx in Doc venv
-      #   run: |
-      #     ./Doc/venv/bin/pip install git+https://github.com/revisto/sphinx.git
+      - name: Install custom Sphinx in Doc venv
+        run: |
+          ./Doc/venv/bin/pip install git+https://github.com/revisto/sphinx.git@stable/v8.2.3-rtl
           
       - name: Checkout translation files
         uses: actions/checkout@v4