chore: fix phpstan errors

src/Service/BookingChangeTracker.php

@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Service;
 
+use App\BusProNet\Model\Service;
 use App\Form\Model\BookingDto;
 use App\Form\Model\ParticipantDto;
 
@@ -36,7 +37,7 @@ class BookingChangeTracker
      *
      * @param BookingDto $bookingDto The booking DTO to extract data from
      *
-     * @return array Serializable array of all user-editable data
+     * @return array<string, mixed> Serializable array of all user-editable data
      */
     public function extractUserData(BookingDto $bookingDto): array
     {
@@ -61,7 +62,7 @@ class BookingChangeTracker
      *
      * @param ParticipantDto $participant The participant to extract data from
      *
-     * @return array Serializable array of participant data
+     * @return array<string, mixed> Serializable array of participant data
      */
     private function extractParticipantData(ParticipantDto $participant): array
     {
@@ -120,9 +121,9 @@ class BookingChangeTracker
      * This ensures that associative arrays, indexed arrays, and different orders
      * all produce the same fingerprint as long as the same services are present.
      *
-     * @param array $services Array of Service objects
+     * @param list<Service> $services Array of Service objects
      *
-     * @return array Sorted array of service IDs
+     * @return list<int|null> Sorted array of service IDs
      */
     private function normalizeServiceArray(array $services): array
     {
@@ -130,7 +131,7 @@ class BookingChangeTracker
         $ids = array_unique($ids);
         sort($ids);
 
-        return array_values($ids);
+        return $ids;
     }
 
     /**