fix: don't show incorrect notification about updated rentals

src/Form/Service/ParticipantRentalsFieldHandler.php

@@ -96,7 +96,9 @@ class ParticipantRentalsFieldHandler extends AbstractParticipantFieldHandler
         );
 
         // Notify if rentals were cleared due to skipass duration change
-        if ([] !== $previousRentals && [] === $validSelections) {
+        // Only show notification if user had submitted rentals that got filtered out,
+        // not if the user intentionally cleared the selection (empty submission)
+        if ([] !== $previousRentals && [] === $validSelections && [] !== $selectedRentals) {
             $participant->addNotification(
                 'warning',
                 'Ausrüstung wurde entfernt (andere Skipass-Dauer ausgewählt)'