ci/cirrus: use python 3.8 and 3.9

.cirrus.yml

@@ -7,8 +7,8 @@ test_task:
   skip: "!changesInclude('.cirrus.yml', 'poetry.lock', 'pyproject.toml', '**.json','**.py')"
   env:
     matrix:
-      - PYTHON: python3.6
       - PYTHON: python3.8
+      - PYTHON: python3.9
   python_script:
     - PYPACKAGE=$(printf '%s' $PYTHON | tr -d '.')
     - SQLPACKAGE=$(printf '%s-sqlite3' $PYPACKAGE | sed 's/thon//')