[Form][TwigBridge] Don't render _method in form_rest() for a child form

src/Symfony/Bridge/Twig/Resources/views/Form/form_div_layout.html.twig

@@ -303,7 +303,7 @@
         {% endif %}
     {%- endfor %}
 
-    {% if not form.methodRendered %}
+    {% if not form.methodRendered and form.parent is null %}
         {%- do form.setMethodRendered() -%}
         {% set method = method|upper %}
         {%- if method in ["GET", "POST"] -%}