Extract feature promotion logic to a variable

ee/app/helpers/ee/boards_helper.rb

@@ -5,6 +5,10 @@ module EE
     end
 
     def board_data
+      show_feature_promotion = (@project && show_promotions? &&
+                                (!@project.feature_available?(:multiple_issue_boards) ||
+                                 !@project.feature_available?(:scoped_issue_board) ||
+                                 !@project.feature_available?(:issue_board_focus_mode))).to_s
       data = {
         board_milestone_title: board&.milestone&.title,
         board_author_username: board&.author&.username,
@@ -13,7 +17,7 @@ module EE
         labels: board&.labels.to_json(only: [:id, :title, :color] ),
         board_weight: board&.weight,
         focus_mode_available: parent.feature_available?(:issue_board_focus_mode).to_s,
-        show_promotion: (@project && show_promotions? && (!@project.feature_available?(:multiple_issue_boards) || !@project.feature_available?(:scoped_issue_board) || !@project.feature_available?(:issue_board_focus_mode))).to_s
+        show_promotion: show_feature_promotion
       }
 
       super.merge(data)