Avoid array_key_exists() check on objects.

PHP 7.4 throws deprecation error for such usage.

src/Utility/Hash.php

@@ -253,8 +253,13 @@ class Hash
                 return false;
             }
 
+            if (is_array($data)) {
+                $attrPresent = array_key_exists($attr, $data);
+            } else {
+                $attrPresent = $data->offsetExists($attr);
+            }
             // Empty attribute = fail.
-            if (!(isset($data[$attr]) || array_key_exists($attr, $data))) {
+            if (!$attrPresent) {
                 return false;
             }