Add Python 3.12 to CI (#842)

Author: frenck

.github/workflows/tests.yaml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ["3.11"]
+        python: ["3.11", "3.12"]
     steps:
       - name: ⤵️ Check out code from GitHub
         uses: actions/[email protected]