Remove unused before block from settings/branding spec (#27759)

.rubocop_todo.yml

@@ -55,7 +55,6 @@ RSpec/AnyInstance:
     - 'spec/controllers/activitypub/inboxes_controller_spec.rb'
     - 'spec/controllers/admin/accounts_controller_spec.rb'
     - 'spec/controllers/admin/resets_controller_spec.rb'
-    - 'spec/controllers/admin/settings/branding_controller_spec.rb'
     - 'spec/controllers/auth/sessions_controller_spec.rb'
     - 'spec/controllers/settings/two_factor_authentication/confirmations_controller_spec.rb'
     - 'spec/controllers/settings/two_factor_authentication/recovery_codes_controller_spec.rb'

spec/controllers/admin/settings/branding_controller_spec.rb

@@ -19,10 +19,6 @@ RSpec.describe Admin::Settings::BrandingController do
     end
 
     describe 'PUT #update' do
-      before do
-        allow_any_instance_of(Form::AdminSettings).to receive(:valid?).and_return(true)
-      end
-
       around do |example|
         before = Setting.site_short_description
         Setting.site_short_description = nil