refactor(app): Update MusicManager singleton registration

- Removed MusicManager::class from singletons array in AppServiceProvider.php
- Added MusicManager::class to singletons in bootstrap/app.php

app/Providers/AppServiceProvider.php

@@ -35,7 +35,7 @@ final class AppServiceProvider extends ServiceProvider
      * @var array<class-string|int, class-string>
      */
     public array $singletons = [
-        MusicManager::class,
+        // MusicManager::class,
     ];
 
     /**

bootstrap/app.php

@@ -11,6 +11,7 @@
  * @see https://github.com/guanguans/music-dl
  */
 
+use App\MusicManager;
 use Illuminate\Foundation\Configuration\Exceptions;
 use Illuminate\Log\LogManager;
 use LaravelZero\Framework\Application;
@@ -33,4 +34,7 @@
             }
         });
     })
+    ->withSingletons([
+        MusicManager::class,
+    ])
     ->create();