Update MWPS test to avoid transient failures

This updates the test to remove the check for UI state that doesn't
reliably appear exactly when the test expects. It would be better
to test in a dedicated transient test.

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

@@ -69,14 +69,15 @@ module QA
         Page::MergeRequest::Show.perform do |mr|
           mr.merge_when_pipeline_succeeds!
 
-          expect(mr.merge_request_status).to match(/to be merged automatically when the pipeline succeeds/)
-
           Support::Waiter.wait_until(sleep_interval: 5) do
             merge_request = merge_request.reload!
             merge_request.state == 'merged'
           end
 
-          expect(mr.merged?).to be_truthy, "Expected content 'The changes were merged' but it did not appear."
+          aggregate_failures do
+            expect(merge_request.merge_when_pipeline_succeeds).to be_truthy
+            expect(mr.merged?).to be_truthy, "Expected content 'The changes were merged' but it did not appear."
+          end
         end
       end
     end