Update OptimizeHeroImages::generateImg() to add fetchpriority attr …

…on hero images

src/Optimizer/Transformer/OptimizeHeroImages.php

@@ -555,6 +555,7 @@ private function generateImg(HeroImage $heroImage, Document $document)
         $imgElement = $document->createElement(Tag::IMG);
         $imgElement->setAttribute(Attribute::CLASS_, self::SSR_IMAGE_CLASS);
         $imgElement->setAttribute(Attribute::DECODING, 'async');
+        $imgElement->setAttribute(Attribute::FETCHPRIORITY, 'high');
 
         // If the image was detected as hero image candidate (and thus lacks an explicit data-hero), mark it as a hero
         // and add loading=lazy to guard against making the page performance even worse by eagerly loading an image