Fix CI version for 3.12; drop 3.8

(Python 3.8 lacks PyType_FromModuleAndSpec API)

Author: 1st1

.github/workflows/tests.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12.0-beta.4"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         os: [windows-latest, ubuntu-latest, macos-latest]
         arch: [x64, x86]
         exclude: