fix: phpstan error

Author: GigaGiorgadze

src/Components/Forms/PageBuilder.php

@@ -350,7 +350,7 @@ public function relationship(
                     return [
                         ...$item,
                         'data' => json_encode($item['data'] ?? []),
-                        "{$relationshipName}_id" => $record->id,
+                        "{$relationshipName}_id" => $record->getKey(),
                         "{$relationshipName}_type" => $record->getMorphClass(),
                     ];
                 }, $state), uniqueBy: ['id'], update: ['data', 'order', 'updated_at']);