run tests on py3.10

PypI pkg will still be compiled for py3.9 (pretty sure)

.github/workflows/test.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: 3.9
+          python-version: "3.10"
           cache: pip
           cache-dependency-path: pyproject.toml