Update page object method name

The new name should be clearer and less awkward

qa/qa/ee/page/merge_request/show.rb

@@ -256,7 +256,7 @@ module QA
             approvals_content.match(/Requires (\d+) more approvals/)[1].to_i
           end
 
-          def merge_merge_train_immediately
+          def skip_merge_train_and_merge_immediately
             click_element :merge_moment_dropdown
             click_element :merge_immediately_option
 

qa/qa/specs/features/ee/browser_ui/6_release/pipelines_for_merged_results_and_merge_trains_spec.rb

@@ -74,8 +74,8 @@ module QA
           expect(pipeline_passed).to be_truthy, "Expected the merged result pipeline to pass."
 
           # The default option is to merge via merge train,
-          # but that will be covered by another test
-          show.merge_merge_train_immediately
+          # but that is covered by the 'merges via a merge train' test
+          show.skip_merge_train_and_merge_immediately
         end
 
         merged = Page::MergeRequest::Show.perform(&:merged?)