chore: fix phpstan errors

src/Form/Service/ParticipantBoardFieldHandler.php

@@ -89,6 +89,10 @@ class ParticipantBoardFieldHandler extends AbstractParticipantFieldHandler
         $participant->board = $validSelections;
     }
 
+    /**
+     * @param array<int, Service> $availableBoard
+     * @param list<Service>       $validSelections
+     */
     private function updateAutoBookOptOutBoard(
         ParticipantDto $participant,
         array $availableBoard,
@@ -98,10 +102,6 @@ class ParticipantBoardFieldHandler extends AbstractParticipantFieldHandler
     ): void {
         $currentlySelectedAutoBookIds = [];
         foreach ($participant->board as $selectedService) {
-            if (false === $selectedService instanceof Service) {
-                continue;
-            }
-
             if (null === $selectedService->id || true === $selectedService->mandatory || false === $selectedService->autoBook) {
                 continue;
             }
@@ -135,6 +135,12 @@ class ParticipantBoardFieldHandler extends AbstractParticipantFieldHandler
         ));
     }
 
+    /**
+     * @param list<mixed>         $selectedServices
+     * @param array<int, Service> $availableServices
+     *
+     * @return list<Service>
+     */
     private function filterValidServiceSelections(
         array $selectedServices,
         array $availableServices,
@@ -156,6 +162,9 @@ class ParticipantBoardFieldHandler extends AbstractParticipantFieldHandler
         return $validSelections;
     }
 
+    /**
+     * @param array<int, Service> $availableServices
+     */
     private function isServiceValidForParticipant(
         mixed $selectedService,
         array $availableServices,