feat: upgrade phpunit to 12.5

tests/Service/AccommodationBookingBreakdownCalculatorTest.php

@@ -141,7 +141,7 @@ class AccommodationBookingBreakdownCalculatorTest extends TestCase
                 'undersubscription40Eur' => 0,
                 'undersubscription40Chf' => 0,
             ]),
-            $priceRepository ?? $this->createMock(AccommodationPriceRepository::class),
+            $priceRepository ?? $this->createStub(AccommodationPriceRepository::class),
         );
     }
 }