Removed the vi format comments from the source

Vim users can use the [editorconfig plugin](https://github.com/editorconfig/editorconfig-vim) to automatically set tab spacing for the SDL coding style.

Fixes https://github.com/libsdl-org/SDL/issues/6903

VisualC-GDK/tests/testgdk/src/testgdk.cpp

@@ -500,5 +500,3 @@ main(int argc, char *argv[])
     SDL_free(soundname);
     return 0;
 }
-
-/* vi: set ts=4 sw=4 expandtab: */