feat: implement hx-boost for reliable loading indication

src/Controller/Booking/Create/Step4Controller.php

@@ -104,7 +104,7 @@ class Step4Controller extends AbstractController
                 $this->clearTravelDataCache($bookingCreateDto);
                 $this->bookingService->clearBookingDto($request, BookingDto::MODE_CREATE);
 
-                return $this->hxRedirect($request, $this->generateUrl('app_booking_create_success'));
+                return $this->redirectToRoute('app_booking_create_success');
             } catch (TimeoutException $e) {
                 return $this->handleApiError(
                     'Booking creation timeout',