ENGCOM-6064: Remove try-catch construction #1002

 - Merge Pull Request magento/graphql-ce#1002 from TomashKhamlai/graphql-ce:coverage-downloadable-links-data-provider
 - Merged commits:
   1. 7dc9e64
   2. f45a672

Author: magento-engcom-team

app/code/Magento/DownloadableGraphQl/Model/Cart/BuyRequest/DownloadableLinksDataProvider.php

@@ -40,12 +40,7 @@ public function execute(array $cartItemData): array
 
         if (isset($cartItemData['data']) && isset($cartItemData['data']['sku'])) {
             $sku = $cartItemData['data']['sku'];
-
-            try {
-                $product = $this->productRepository->get($sku);
-            } catch (NoSuchEntityException $e) {
-                throw new GraphQlNoSuchEntityException(__('Could not find specified product.'));
-            }
+            $product = $this->productRepository->get($sku);
 
             if ($product->getLinksPurchasedSeparately() && isset($cartItemData['downloadable_product_links'])) {
                 $downloadableLinks = $cartItemData['downloadable_product_links'];

dev/tests/api-functional/testsuite/Magento/GraphQl/ConfigurableProduct/AddConfigurableProductToCartTest.php

@@ -265,7 +265,8 @@ public function testAddNonExistentConfigurableProductVariationToCart()
 
         $this->expectException(\Exception::class);
         $this->expectExceptionMessage(
-            'Could not add the product with SKU configurable to the shopping cart: Could not find specified product.'
+            'Could not add the product with SKU configurable to the shopping cart: The product that was requested ' .
+            'doesn\'t exist. Verify the product and try again.'
         );
 
         $this->graphQlMutation($query);