ci: add python 3.12 as test target

To make sure the code works with newer python versions.

.github/workflows/pr.yaml

@@ -25,7 +25,7 @@ jobs:
           --health-retries 5
     strategy:
       matrix:
-        python: ["3.10"]
+        python: ["3.10", "3.12"]
     steps:
       - name: Setup Python
         uses: actions/setup-python@v2