use python 3.9 in workflow

Author: jordanstephens

.github/workflows/deploy.yaml

@@ -14,6 +14,10 @@ jobs:
     environment: production
 
     steps:
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.9'
       - name: Checkout Repo
         uses: actions/checkout@v4