Clean up pages delete service specs

This feature flag was removed a long time ago

spec/services/pages/delete_services_spec.rb

@@ -3,7 +3,6 @@
 require 'spec_helper'
 
 RSpec.describe Pages::DeleteService do
-  shared_examples 'remove pages' do
   let_it_be(:project) { create(:project, path: "my.project")}
   let_it_be(:admin) { create(:admin) }
   let_it_be(:domain) { create(:pages_domain, project: project) }
@@ -25,13 +24,4 @@ RSpec.describe Pages::DeleteService do
 
     expect(project.reload.pages_domains.count).to be 0
   end
-  end
-
-  context 'with feature flag enabled' do
-    before do
-      expect(PagesRemoveWorker).to receive(:perform_async).and_call_original
-    end
-
-    it_behaves_like 'remove pages'
-  end
 end