feat: implement hx-boost for reliable loading indication

src/Controller/Booking/Traits/ParticipantCardFlowTrait.php

@@ -114,7 +114,6 @@ trait ParticipantCardFlowTrait
         BookingDto $bookingDto,
         int $index,
         string $refreshRouteName,
-        string $submitRouteName,
     ): Response {
         // Create form with validation disabled
         $form = $this->createParticipantForm($bookingDto, $index, [
@@ -143,7 +142,6 @@ trait ParticipantCardFlowTrait
                 'bookingDto' => $bookingDto,
                 'summaryData' => $summaryData,
                 'refreshRouteName' => $refreshRouteName,
-                'submitRouteName' => $submitRouteName,
             ]
         );