remove python3.12 from CI for now

3.12 needs cantera update, which is not yet ready.

Author: jonwzheng

.github/workflows/CI.yml

@@ -63,7 +63,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11"]
         os: [macos-13, macos-latest, ubuntu-latest]
         include-rms: ["", "with RMS"]
         exclude: