Use Python 3.13 for unittest

Author: smathot

.github/workflows/run-unittests.yaml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10"]
+        python-version: ["3.13"]
 
     steps:
       - uses: actions/checkout@v3