Remove unnecessary 'pass' statement

ref: https://lgtm.com/projects/g/godotengine/godot/?mode=tree&ruleFocus=910088
(cherry picked from commit 2e0044c93d5360c23af30fe7014b2c33fcd06012)

platform/windows/detect.py

@@ -168,7 +168,6 @@ def setup_mingw(env):
     """Set up env for use with mingw"""
     # Nothing to do here
     print("Using MinGW")
-    pass
 
 
 def configure_msvc(env, manual_msvc_config):