Add python 3.12 to CI

Author: titusz

.github/workflows/test.yml

@@ -6,7 +6,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.7, 3.8, 3.9, '3.10', '3.11']
+        python-version: [3.7, 3.8, 3.9, '3.10', '3.11', '3.12']
         os: [ubuntu-20.04, macos-11, macos-12, windows-2019]
     runs-on: ${{ matrix.os }}
     steps: