Update python.yml

Need to fix workflow as well, since it still used the old-fashioned way of installing (i.e. `python setup.py install`, instead of `pip install .`)

.github/workflows/python.yml

@@ -8,10 +8,10 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.9", "3.10"]
+        python-version: ["3.8", "3.9", "3.10", "3.11"]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
@@ -21,6 +21,6 @@ jobs:
           python -m pip install --upgrade pip
           pip install flake8 pytest
       - name: Install
-        run: python setup.py install
+        run: pip install .
       - name: Test
-        run: python setup.py test
+        run: pytest