add setup-python action

Author: johnjeffers

.github/workflows/deploy.yaml

@@ -9,7 +9,7 @@ on:
         options:
           - publish  # build & publish to pypi
           - release  # build & release to svn
-        default: build
+        default: publish
 
 permissions:
   contents: read
@@ -25,6 +25,11 @@ jobs:
       - name: checkout
         uses: actions/checkout@v4
 
+      - name: setup python
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.12.6
+
       - name: setup java
         uses: actions/setup-java@v4
         with: