Thumbnail generation script causes games to crash, causing generation to fail

The thumbnail generation script overrides some functions with no-ops when running games. For example, setTune, for games running within the script, is set to `() => {}`. This causes some thumbnails to fail to generate, as seen below, when the return values of these functions are accessed (in this case: `playTune().end()`

Relevant file: src/integrations/thumbnail.ts