Test pn py 3.12

Author: pgleeson

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [ "3.9", "3.10", "3.11"]
+        python-version: [ "3.9", "3.11", "3.12"]
         runs-on: [ubuntu-latest, macos-latest, windows-latest]
         exclude:
           - runs-on: macos-latest