Prevent breakage when switching to PROD, with {{ dump }} in the templates

config/services.yaml

@@ -67,7 +67,9 @@ services:
             - { name: knp_menu.menu_builder, method: createAdminMenu, alias: admin_menu } # The alias is what is used to retrieve the menu
 
     Bolt\Menu\BackendMenuBuilderInterface: '@Bolt\Menu\BackendMenuBuilder'
+
     Bolt\Menu\FrontendMenuBuilder: ~
+    
     Bolt\Menu\FrontendMenuBuilderInterface: '@Bolt\Menu\FrontendMenuBuilder'
 
     # Needed for SetContent from bolt/core

src/Twig/DumpExtension.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Bolt\Twig;
+
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFunction;
+
+/**
+ * Dump Twig extension.
+ *
+ * This is a (deliberately) empty extension. When the implementor switched a
+ * site from DEV to PROD, it shouldn't break if there's a lingering `{{ dump }}`
+ * left in the site. This Twig Extension acts as a fallback to prevent that.
+ */
+class DumpExtension extends AbstractExtension
+{
+    public function getFunctions(): array
+    {
+        return [
+            new TwigFunction('dump', [$this, 'dump']),
+        ];
+    }
+
+    public function dump(): void
+    {
+    }
+}