Remove try-catch construction

As long as
```graphql
type Mutation {
    addDownloadableProductsToCart(input: AddDownloadableProductsToCartInput): AddDownloadableProductsToCartOutput @resolver(class: "Magento\\QuoteGraphQl\\Model\\Resolver\\AddSimpleProductsToCart")
}
```
is not changed, this exception caching is a duplicate of one that is in \Magento\QuoteGraphQl\Model\Resolver\AddSimpleProductsToCart::execute();

Signed-off-by: Tomash Khamlai <tomash.khamlai@gmail.com>

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'];