CI: Test on Python 3.12

Author: effigies

.github/workflows/travis.yml

@@ -79,7 +79,7 @@ jobs:
     strategy:
       max-parallel: 5
       matrix:
-        python-version: ['3.8', '3.9',  '3.10',  '3.11']
+        python-version: ['3.8', '3.9',  '3.10',  '3.11', '3.12']
     steps:
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4