* Fixes gondolas turning invisible when given a pet collar. (#54791)
Gondolas exist as a composite of overlays with a null icon_state.
When you put a pet collar on a gondola, it deletes all the existing overlays, rendering the gondola invisible.
I just overrode the regenerate_icons proc to do nothing for gondolas, because the parent proc is utterly useless to us and we don't need its functionality.
* Fixes gondolas turning invisible when given a pet collar.
Co-authored-by: Timberpoes <silent_insomnia_pp@hotmail.co.uk>