Use #[Autowire] attribute in FileUploader service example

Replaced the YAML-based injection of the uploads_directory parameter with the #[Autowire] attribute directly in the FileUploader constructor. This avoids service configuration issues and ensures the example works out of the box with modern Symfony versions.

Author: foybkaa

controller/upload_file.rst

@@ -240,7 +240,7 @@ logic to a separate service::
     class FileUploader
     {
         public function __construct(
-            private string $targetDirectory,
+            #[Autowire('%brochures_directory%')] private string $targetDirectory,
             private SluggerInterface $slugger,
         ) {
         }