Fix Lint/EmptyClass cop (#24795)

.rubocop_todo.yml

@@ -159,11 +159,6 @@ Lint/EmptyBlock:
     - 'spec/models/user_role_spec.rb'
     - 'spec/models/web/setting_spec.rb'
 
-# Configuration parameters: AllowComments.
-Lint/EmptyClass:
-  Exclude:
-    - 'spec/controllers/api/base_controller_spec.rb'
-
 Lint/NonLocalExitFromIterator:
   Exclude:
     - 'app/helpers/jsonld_helper.rb'

spec/controllers/api/base_controller_spec.rb

@@ -2,9 +2,11 @@
 
 require 'rails_helper'
 
-class FakeService; end
-
 describe Api::BaseController do
+  before do
+    stub_const('FakeService', Class.new)
+  end
+
   controller do
     def success
       head 200