Bump Python version so that tomllib is included

This way versioneer can read pyproject.toml

Author: maresb

.github/workflows/pypi.yml

@@ -67,7 +67,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: '3.10'
+          python-version: '3.11'
 
       - name: Install dependencies
         run: pip install numpy versioneer