Merge pull request #4285 from mamhoff/faster-create-item-adjustments

Promotion Rule CreateItemAdjustments: Use in-memory objects

core/app/models/spree/promotion/actions/create_item_adjustments.rb

@@ -83,13 +83,8 @@ def ensure_action_has_calculator
         end
 
         def line_items_to_adjust(promotion, order)
-          excluded_ids = adjustments.
-            where(adjustable_id: order.line_items.pluck(:id), adjustable_type: 'Spree::LineItem').
-            pluck(:adjustable_id).
-            to_set
-
           order.line_items.select do |line_item|
-            !excluded_ids.include?(line_item.id) &&
+            line_item.adjustments.none? { |adjustment| adjustment.source == self } &&
               promotion.line_item_actionable?(order, line_item)
           end
         end