chore: code refactor via rector

config/app.php

@@ -33,7 +33,7 @@ return [
     'fetch_from_db' => env('FETCH_FETCH_FOR_DB', false),
     'fetch_from_remote_db' => env('FETCH_FROM_REMOTE_DB', false),
     'force_db_mail' => env('FORCE_DB_MAIL', false),
-    'move_or_delete' => env('MOVE_OR_DELETE', null),
+    'move_or_delete' => env('MOVE_OR_DELETE'),
     'auto_fetch_mail' => env('AUTO_FETCH_MAIL', false),
 
     'notify_tg_bot_token' => env('NOTIFY_TG_BOT_TOKEN', ''),
@@ -114,7 +114,7 @@ return [
 
     'previous_keys' => [
         ...array_filter(
-            explode(',', env('APP_PREVIOUS_KEYS', ''))
+            explode(',', (string) env('APP_PREVIOUS_KEYS', ''))
         ),
     ],