Fix user_filter_issues_spec when vue_issuables_list ff is off

spec/features/issues/user_filters_issues_spec.rb

@@ -2,13 +2,11 @@
 
 require 'spec_helper'
 
-RSpec.describe 'User filters issues' do
+RSpec.describe 'User filters issues', :js do
   let_it_be(:user) { create(:user) }
   let_it_be(:project) { create(:project_empty_repo, :public) }
 
   before do
-    stub_feature_flags(vue_issuables_list: false)
-
     %w[foobar barbaz].each do |title|
       create(:issue,
              author: user,