Add Checkout and setup Python action to deploy step. (#206)

Author: smithdc1

.github/workflows/publish.yml

@@ -42,6 +42,11 @@ jobs:
     permissions:
       id-token: write  # IMPORTANT: this permission is mandatory for trusted publishing
     steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
       - name: build
         run: |
           python -m pip install build