Update main.yml

Author: jph00

.github/workflows/main.yml

@@ -80,7 +80,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v3
       with:
-        python-version: '3.9'
+        python-version: '3.11'
     - name: clone this branch [fastcore]
       uses: actions/checkout@v3
       with: