ci: add python3.12 to test matrix

Author: nats

.github/workflows/checks.yml

@@ -10,7 +10,7 @@ jobs:
   test:
     strategy:
       matrix:
-        python: [ "3.8", "3.9", "3.10", "3.11" ]
+        python: [ "3.8", "3.9", "3.10", "3.11", "3.12" ]
         os: [ ubuntu-latest, macos-latest, windows-latest ]
     runs-on: ${{ matrix.os }}
     steps: