Add a check to ensure cached code/routes exist before including them

src/ServiceProvider.php

@@ -53,6 +53,10 @@ public function register(): void
     /** @return Builder[] */
     private function instantiateBuilders(): array
     {
+        if (!file_exists(config('membrane.routes_file')) || empty(config('membrane.additional_builders'))) {
+            return [];
+        }
+
         /** @phpstan-ignore-next-line */ // config is a laravel framework helper method
         $router = new Router(new RouteCollection(include config('membrane.routes_file')));