Update Python version matrix in CI workflow

Author: baseplate-admin

.github/workflows/CI.yml

@@ -44,7 +44,7 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                python-version: ['3.10', '3.11', '3.12', '3.13', 'pypy-3.10', 'pypy-3.11']
+                python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', 'pypy-3.10', 'pypy-3.11']
                 postgres-version: ['14', '15', '16', '17', '18']
         services:
             database: