Update MWPS to get more info on failure

qa/qa/page/merge_request/show.rb

@@ -263,7 +263,8 @@ module QA
           # status as unmerged, the test will fail.
           # Revisit after merge page re-architect is done https://gitlab.com/groups/gitlab-org/-/epics/5598
           # To remove page refresh logic if possible
-          retry_until(max_attempts: 3, reload: true) do
+          # We don't raise on failure because this method is used as a predicate matcher
+          retry_until(max_attempts: 3, reload: true, raise_on_failure: false) do
             has_element?(:merged_status_content, text: 'The changes were merged into', wait: 20)
           end
         end

qa/qa/specs/features/browser_ui/3_create/merge_request/merge_when_pipeline_succeeds_spec.rb

@@ -88,7 +88,7 @@ module QA
               mr.wait_until_ready_to_merge(transient_test: transient_test)
 
               mr.retry_until(reload: true, message: 'Wait until ready to click MWPS') do
-                merge_request = merge_request.reload!
+                merge_request.reload!
 
                 # Don't try to click MWPS if the MR is merged or the pipeline is complete
                 break if merge_request.state == 'merged' || mr.wait_until { project.pipelines.last }[:status] == 'success'
@@ -102,8 +102,10 @@ module QA
               end
 
               aggregate_failures do
-                expect(mr.merged?).to be_truthy, "Expected content 'The changes were merged' but it did not appear."
+                expect { mr.merged? }.to eventually_be_truthy.within(max_duration: 60), "Expected content 'The changes were merged' but it did not appear."
                 expect(merge_request.reload!.merge_when_pipeline_succeeds).to be_truthy
+                expect(merge_request.state).to eq('merged')
+                expect(project.pipelines.last[:status]).to eq('success')
               end
             end
           end