chore: recover container prop

framework/core/src/Foundation/AbstractServiceProvider.php

@@ -9,9 +9,17 @@
 
 namespace Flarum\Foundation;
 
+use Illuminate\Contracts\Foundation\Application as ApplicationContract;
 use Illuminate\Support\ServiceProvider;
 
 abstract class AbstractServiceProvider extends ServiceProvider
 {
-    //
+    protected ApplicationContract $container;
+
+    public function __construct(ApplicationContract $app)
+    {
+        parent::__construct($app);
+
+        $this->container = $app;
+    }
 }