test with python 3.9

Author: harminius

.github/workflows/autotests.yml

@@ -15,7 +15,7 @@ jobs:
 
       - uses: actions/setup-python@v2
         with:
-          python-version: "3.10"
+          python-version: "3.9"
 
       - name: Install python package dependencies
         run: |