Changing `Rubicure#Series#girls` and `Precure.all_girls` behavior

[sue445]

Now, Precure.hirogaru_sky.girls.map(&:precure_name) returns Cure Wing

Precure.hirogaru_sky.girls.map(&:precure_name)
# => ["キュアスカイ", "キュアプリズム", "キュアウィング", "キュアバタフライ"]

This is same to Precure.all_girls

Precure.all_girls.include?(Cure.wing)
# => true

But Cure Wing is a boy 👦 , so it feels strange.

So I'm going to change this behavior in the next major version (v4)