Split off from #3, though multiple people have requested this.

Makes Phantoms spawn in all End biomes aside from "The End" (the central island's biome) to provide a proper way to acquire Phantom Membranes when doInsomnia gamerule is false.
All other mods that do this either add entirely new "End Phantom" mobs, making it less of a spawn tweak and more of an entirely new mob mod, or are Forge-only. honestly was trying to figure out how to do this myself but i can't wrap my head around fabric, am too rusty with Java.