fix: misc fixes

[perappu]

• remove old evolution image code that isn't needed anymore (or at least, not in this form.... there's an issue rn where if you switch a pet's variant while it's evolved it'll keep the old evolution ID. there needs to be some kind of evolution equivalency logic or like make it reset the evolution or something when switching variants. idk need to think on it more)
• switching to default variant with a splice item fixes
• throw an error if you try to delete a pet with extant children