Fix: Enclose Python version in quotes for consistency in deploy workflow

Author: jonasvdd

.github/workflows/deploy-mkdocs.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.10
+          python-version: '3.10'
 
       - name: Install Poetry
         uses: snok/install-poetry@v1