test all 5 python versions in unit tests

Author: SaundersR1999

.github/workflows/ci.yaml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
 
     steps:
       - name: Checkout code