run tests on multiple python versions

Author: frankh

.github/workflows/ci.yml

@@ -47,18 +47,21 @@ jobs:
                   mypy --no-site-packages --config-file mypy.ini  . | mypy-baseline filter
 
     tests:
-        name: Python tests
+        name: Python ${{ matrix.python-version }} tests
         runs-on: ubuntu-latest
+        strategy:
+            matrix:
+                python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
 
         steps:
             - uses: actions/checkout@v2
               with:
                   fetch-depth: 1
 
-            - name: Set up Python 3.9
+            - name: Set up Python ${{ matrix.python-version }}
               uses: actions/setup-python@v2
               with:
-                  python-version: 3.9
+                  python-version: ${{ matrix.python-version }}
 
             - name: Install requirements.txt dependencies with pip
               run: |