Quarantine tests that are very flaky

Signed-off-by: Rémy Coutable <remy@rymai.me>

ee/spec/features/issues/form_spec.rb

@@ -52,7 +52,7 @@ describe 'New/edit issue', :js do
         wait_for_requests
       end
 
-      it 'displays selected users even if they are not part of the original API call' do
+      it 'displays selected users even if they are not part of the original API call', quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/28634' do
         find('.dropdown-input-field').native.send_keys user2.name
 
         page.within '.dropdown-menu-user' do

spec/features/merge_request/user_posts_diff_notes_spec.rb

@@ -56,7 +56,7 @@ describe 'Merge request > User posts diff notes', :js do
     end
 
     context 'with an unchanged line on the left and an unchanged line on the right' do
-      it 'allows commenting on the left side' do
+      it 'allows commenting on the left side', quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/196826' do
         should_allow_commenting(find('[id="2f6fcd96b88b36ce98c38da085c795a27d92a3dd_7_7"]', match: :first).find(:xpath, '..'), 'left')
       end
 

spec/features/merge_request/user_sees_diff_spec.rb

@@ -76,7 +76,7 @@ describe 'Merge request > User sees diff', :js do
     end
 
     context 'as user who needs to fork' do
-      it 'shows fork/cancel confirmation', :sidekiq_might_not_need_inline do
+      it 'shows fork/cancel confirmation', :sidekiq_might_not_need_inline, quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/196749' do
         sign_in(user)
         visit diffs_project_merge_request_path(project, merge_request)
 

spec/support/features/discussion_comments_shared_example.rb

@@ -269,7 +269,7 @@ shared_examples 'thread comments' do |resource_name|
             end
           end
 
-          it 'has "Comment" selected when opening the menu' do
+          it 'has "Comment" selected when opening the menu', quarantine: 'https://gitlab.com/gitlab-org/gitlab/issues/196825' do
             find(toggle_selector).click
 
             find("#{menu_selector} li", match: :first)