update setup pyflake8

.github/workflows/main.yaml

@@ -13,7 +13,9 @@ jobs:
         uses: actions/checkout@v5.0.0
 
       - name: Run tests
-        run: python3 test_main.py
+        run: |
+          apt update
+          python3 test_main.py
 
       - name: setup pyflake8
         run: |