test: use tox env in lint workflow

.github/workflows/lint.yml

@@ -12,9 +12,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Install flake8
+      - name: Install tox
         run: |
-          python3 -m pip install flake8
-      - name: Run flake8
+          python -m pip install tox
+      - name: Run tox
         run: |
-          python3 -m flake8
+          python -m tox run -e lint