ci: Fix flake8 workflow configuration

Author: enwask

.github/workflows/flake8.yml

@@ -24,7 +24,7 @@ jobs:
     - name: Set up Python 3.10
       uses: actions/setup-python@v5
       with:
-        python-version: 3.10
+        python-version: "3.10"
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip