Add Python 3.12 (#774)

Author: Dreamsorcerer

.github/workflows/ci.yml

@@ -50,7 +50,7 @@ jobs:
     name: Test
     strategy:
       matrix:
-        pyver: ['3.8', '3.9', '3.10', '3.11']
+        pyver: ['3.8', '3.9', '3.10', '3.11', '3.12']
         os: [ubuntu, macos, windows]
         include:
           - pyver: pypy-3.8