Add pep8-naming to our python linting

lib/python/qmk/cli/doctor.py

@@ -39,7 +39,7 @@ def doctor(cli):
                 ok = False
 
     # Determine our OS and run platform specific tests
-    OS = platform.system()
+    OS = platform.system()  # noqa (N806), uppercase name is ok in this instance
 
     if OS == "Darwin":
         cli.log.info("Detected {fg_cyan}macOS.")