Add 3.9 to CI full test, now that it runs faster

Author: ryan-kipawa

.github/workflows/full_test.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.12"]
+        python-version: ["3.9", "3.12"]
 
     steps:
       - uses: actions/checkout@v4