fixes python version in action

Author: GeertvanGeest

.github/workflows/render_page.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: 3.x
+          python-version: '3.10'
       - run: |
           pip install -r requirements.txt
           mkdocs gh-deploy --force