fix errors in tests, fixes #1309

lib/models/resources/ResourcePropertyDefinition.class.php

phpstan.neon.dist

tests/functional/lib/models/resources/BuildingTest.php

tests/functional/lib/models/resources/LocationTest.php

...unctional/lib/models/resources/ResourceAssignmentTest.php

tests/functional/lib/models/resources/ResourceTest.php

tests/functional/lib/models/resources/RoomTest.php

tests/functional/lib/resources/ResourceManagerTest.php

tests/functional/lib/resources/RoomManagerTest.php

tests/jsonapi/BlubberTestHelper.php

tests/jsonapi/CommentsDeleteTest.php

tests/jsonapi/CourseNewsCreateTest.php

tests/jsonapi/ForumEntriesDeleteTest.php

tests/jsonapi/NewsCreateTest.php

tests/jsonapi/NewsDeleteTest.php

tests/unit/lib/FunctionsTest.php

tests/unit/lib/VisualTest.php

tests/unit/lib/classes/AvatarClassTest.php

tests/unit/lib/classes/CronjobScheduleTest.php

tests/unit/lib/classes/CsrfProtectionTest.php