Fix Python version in CI workflow

Author: lexbrugman

.github/workflows/publisher.yaml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: '3.12'
+          python-version: '3.13'
 
       - name: Install dependencies
         run: |