Upgrade unittest to 3.14

Author: dseichter

.github/workflows/unittest.yml

@@ -28,7 +28,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v6
       with:
-        python-version: '3.13'
+        python-version: '3.14'
 
     - name: Install dependencies
       run: |