fix(promotion, types): non discountable items check (#12644)

* fix(promotions): check if item is discountable

* fix: return earl yonly if non discountable

* fix: update test

* chore: add integration test

packages/core/types/src/promotion/common/compute-actions.ts

@@ -180,6 +180,11 @@ export interface ComputeActionItemLine extends Record<string, unknown> {
    */
   subtotal: BigNumberInput
 
+  /**
+   * Whether the line item is discountable.
+   */
+  is_discountable: boolean
+
   /**
    * The adjustments applied before on the line item.
    */