fix: update VCoachList model to change formal_photo type from array to string

app/Models/VCoachList.php

@@ -36,7 +36,7 @@ class VCoachList extends Model
         'health_certificate' => 'array',
         'id_card_front_photo' => 'array',
         'id_card_back_photo' => 'array',
-        'formal_photo' => 'array',
+        'formal_photo' => 'string',
         'health_cert' => 'array',
     ];