Update CI workflow: remove Python 3.8/3.9 from test matrix

Author: jensens

.github/workflows/tests.yaml

@@ -27,10 +27,6 @@ jobs:
           - windows-latest
           - macos-latest
         python-config:
-          - version: "3.8"
-            tox-env: "py38"
-          - version: "3.9"
-            tox-env: "py39"
           - version: "3.10"
             tox-env: "py310"
           - version: "3.11"