use python 3.9

Author: anthony-nhs

.github/workflows/publish.yml

@@ -12,7 +12,7 @@ jobs:
               with:
                   fetch-depth: 0  # This causes all history to be fetched, which is required for calculate-version to function
 
-            - name: Install Python 3.12
+            - name: Install Python 3.9
               uses: actions/setup-python@v5
               with:
                   python-version: 3.12