Rename interface to gdn_interface because it's a defined keyword under windows

test/src/example.h

@@ -31,6 +31,12 @@
 #ifndef EXAMPLE_CLASS_H
 #define EXAMPLE_CLASS_H
 
+// We don't need windows.h in this plugin but many others do and it throws up on itself all the time
+// So best to include it and make sure CI warns us when we use something Microsoft took for their own goals....
+#ifdef WIN32
+#include <windows.h>
+#endif
+
 #include <godot_cpp/classes/control.hpp>
 #include <godot_cpp/classes/global_constants.hpp>
 #include <godot_cpp/classes/viewport.hpp>