Merge branch 'quarantine-burndown-test-waiting-on' into 'master'

Quarantine burndown test waiting on MR

See merge request gitlab-org/gitlab!29720

qa/qa/specs/features/ee/browser_ui/2_plan/burndown_chart/burndown_chart_spec.rb

 # frozen_string_literal: true
 
 module QA
-  context 'Plan', :reliable do
+  context 'Plan', :reliable, quarantine: { issue: 'https://gitlab.com/gitlab-org/gitlab/-/merge_requests/29719', type: :waiting_on } do
     describe 'Burndown chart' do
       include ::QA::Support::Dates