Pokémon Species "Ursaluna" has many `IsDefault=true`

[Utar94]

Steps to Reproduce:

1. Open file api-data/data/api/v2/pokemon-species/901/index.json
2. See lines 226-241: there are 2 default varieties.

[Naramsim]

Hi, I think I spotted the error and proposed a fix: #1275