Skip template dependency install and tests on Python 3.9

Added conditional steps to skip installing py-shiny-templates dependencies and running example app tests for Python 3.9, due to scikit-learn 1.7.0+ requiring Python 3.10 or higher.

Author: karangattu

.github/workflows/pytest.yaml

@@ -200,6 +200,8 @@ jobs:
           path: py-shiny-templates
 
       - name: Install py-shiny-templates dependencies
+        if: matrix.python-version != '3.9'
+        # Scikit-learn 1.7.0+ requires Python 3.10+
         run: |
           make install-py-shiny-templates-deps