update valid python versions for testing

Author: petercorke

.github/workflows/pythonpackage.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9, '3.10']
+        python-version: [3.9, "3.10", 3.11, 3.12, 3.13]
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
@@ -33,10 +33,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.7
+    - name: Set up Python 3.11
       uses: actions/setup-python@v1
       with:
-        python-version: 3.7
+        python-version: 3.11
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip