fix: use correct controller method for redirecting

src/Controller/Administrative/Assignment/CreateController.php

@@ -55,7 +55,7 @@ class CreateController extends AbstractController
                 'job_profile' => $assignment->getJobProfile()->getName(),
             ]);
 
-            return $this->redirectToRoute($returnUrl);
+            return $this->redirect($returnUrl);
         }
 
         return $this->render('administrative/assignment/create.html.twig', [