Projects: update flake8 error codes

The latest flake8 version seems to treat enabling of extensions differently. Need to go back to explicitly enable ATL902 (Copyright check) again. Also add --isolated to make sure no other configuration files are read.

.devcontainer/devcontainer.json

@@ -18,8 +18,10 @@
         "python.linting.pylintEnabled": false,
         "python.linting.flake8Enabled": true,
         "python.linting.flake8Args": [
-            "--select=ATL,ATL902,F,E101,E7,E9,W6",
-            "--ignore=ATL9,E701,E702,E704,E741"
+            "--isolated",
+            "--select ATL,F,E101,E7,E9,W6",
+            "--ignore E701,E702,E704,E741",
+            "--enable-extensions ATL902"
         ]
     },