Fix user generator to fit initial rubocop rules

[FIX rails#53117]

Author: baldarn

railties/lib/rails/generators/rails/authentication/templates/app/models/user.rb

@@ -2,5 +2,5 @@ class User < ApplicationRecord
   has_secure_password
   has_many :sessions, dependent: :destroy
 
-  normalizes :email_address, with: -> e { e.strip.downcase }
+  normalizes :email_address, with: ->(e) { e.strip.downcase }
 end