refactor(phpstand): update coupon code and physical coupon product

This commit modifies the `src/QUI/ERP/Coupons/CouponCode.php` by removing an unexplained variable
annotation.
In `src/QUI/ERP/Coupons/Products/PhysicalCouponProductType.php`, it introduces an import statement
for `QUI\\Locale` and updated the `Locale` parameter type definition in `getTypeDescription`
function. This change improves code readability and consistency.

src/QUI/ERP/Coupons/CouponCode.php

@@ -727,7 +727,6 @@ public function addToOrder(QUI\ERP\Order\OrderInProcess $Order): void
                 continue;
             }
 
-            /* @var $Discount QUI\ERP\Discount\Discount */
             $discounts = $Coupon->getDiscounts();
 
             foreach ($discounts as $Discount) {

src/QUI/ERP/Coupons/Products/PhysicalCouponProductType.php

@@ -3,6 +3,7 @@
 namespace QUI\ERP\Coupons\Products;
 
 use QUI;
+use QUI\Locale;
 
 /**
  * Class PhysicalCouponProductType
@@ -61,7 +62,7 @@ public static function getTypeTitle(null | QUI\Locale $Locale = null): string
     }
 
     /**
-     * @param QUI\Locale $Locale
+     * @param Locale|null $Locale
      * @return string
      */
     public static function getTypeDescription(null | QUI\Locale $Locale = null): string