Prefer 3.x for Python version (latest stable).

Author: jaraco

.github/workflows/main.yml

@@ -113,7 +113,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.11-dev
+          python-version: 3.x
       - name: Install tox
         run: |
           python -m pip install tox