This hasn't worked for a while anyway! Let's remove the bits of code
where we deal with it, and the database field that signals it. (We also
make a corresponding change in Impress 2020, so it doesn't crash trying
to query based on the `prank` column.)
I also ran this snippet to clear out all the Nebula stuff in the db:
```rb
Color.transaction do
nebula = Color.where(prank: true).find_by_name("Nebula")
nebula.pet_types.includes(pet_states: :swf_assets).each do |pet_type|
pet_type.pet_states.each do |pet_state|
pet_state.parent_swf_asset_relationships.each do |psa|
psa.swf_asset.destroy!
psa.destroy!
end
pet_state.destroy!
end
pet_type.destroy!
end
nebula.destroy!
end
```