Update sphinx_build_deploy.yml

add a call to update sphinx before running it to build the documentation

.github/workflows/sphinx_build_deploy.yml

@@ -23,6 +23,10 @@ jobs:
           sudo apt install pandoc
           python -m pip install --upgrade pip
           pip install -r requirements.txt
+          
+      - name: Update Sphinx
+        run: |
+          pip install -U sphinx
 
       - name: Build Sphinx documentation
         run: |