ci: add py3.12 to tests (#887)

Author: woile

.github/workflows/pythonpackage.yml

@@ -6,7 +6,7 @@ jobs:
   python-check:
     strategy:
       matrix:
-        python-version: [ "3.8", "3.9", "3.10", "3.11" ]
+        python-version: [ "3.8", "3.9", "3.10", "3.11", "3.12" ]
         platform: [ ubuntu-20.04, macos-latest, windows-latest ]
     runs-on: ${{ matrix.platform }}
     steps: