fix: remove trailing whitespace in admin files

- Clean up trailing whitespace in app/admin/state.rb
- Clean up trailing whitespace in app/admin/subregions.rb
- Clean up trailing whitespace in app/admin/users.rb
- Adjust formatting in cities_controller.rb for consistency

These changes improve code readability and maintainability by
removing unnecessary whitespace. It is a small clean-up that prepares
files for better version control parsing and reduces the diff clutter.

app/admin/states.rb

@@ -15,5 +15,4 @@ ActiveAdmin.register State do
   #   permitted << :other if params[:action] == 'create' && current_user.admin?
   #   permitted
   # end
-  
 end

app/admin/subregions.rb

@@ -15,5 +15,4 @@ ActiveAdmin.register Subregion do
   #   permitted << :other if params[:action] == 'create' && current_user.admin?
   #   permitted
   # end
-  
 end

app/admin/users.rb

@@ -15,5 +15,4 @@ ActiveAdmin.register User do
   #   permitted << :other if params[:action] == 'create' && current_user.admin?
   #   permitted
   # end
-  
 end

app/controllers/cities_controller.rb

@@ -63,5 +63,4 @@ class CitiesController < ApplicationController
       redirect_to root_path
     end
   end
-
 end