chore: fix rails 8 enum syntax

Author: ElMassimo

playground/vanilla/app/models/song.rb

@@ -2,6 +2,6 @@ class Song < ApplicationRecord
   belongs_to :composer
   has_many :video_clips
 
-  enum genre: {fingerstyle: "fingerstyle", rock: "rock", classical: "classical"}
-  enum tempo: %w[slow medium fast]
+  enum :genre, fingerstyle: "fingerstyle", rock: "rock", classical: "classical"
+  enum :tempo, %w[slow medium fast]
 end