use constructor property promotion

Author: xabbuh

Link.php

@@ -141,8 +141,6 @@ class Link implements EvolvableLinkInterface
     // Extra relations
     public const REL_MERCURE = 'mercure';
 
-    private string $href = '';
-
     /**
      * @var string[]
      */
@@ -153,12 +151,13 @@ class Link implements EvolvableLinkInterface
      */
     private array $attributes = [];
 
-    public function __construct(?string $rel = null, string $href = '')
-    {
+    public function __construct(
+        ?string $rel = null,
+        private string $href = '',
+    ) {
         if (null !== $rel) {
             $this->rel[$rel] = $rel;
         }
-        $this->href = $href;
     }
 
     public function getHref(): string