Fix typo in documentation

Author: yoye

src/LiveComponent/doc/index.rst

@@ -3674,7 +3674,7 @@ uses Symfony's test client to render and make requests to your components::
 
             // Submit form data
             $testComponent
-                ->submitForm(['form' => ['input' => 'value'], 'save');
+                ->submitForm(['form' => ['input' => 'value']], 'save');
 
             $this->assertStringContainsString('Count: 99', $testComponent->render());