add 312 workflow tests

Author: TomDonoghue

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
       MODULE_NAME: specparam
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
 
     steps:
     - uses: actions/checkout@v3