Add tests and classifiers for python 3.12

Update transient deps

Author: enpaul

.github/workflows/ci.yaml

@@ -24,6 +24,8 @@ jobs:
             toxenv: py310
           - version: "3.11"
             toxenv: py311
+          - version: "3.12"
+            toxenv: py312
       fail-fast: true
     steps:
       - name: Checkout