Do not reference enum in constants in tests - compatibility with 8.1

Author: olsavmic

tests/Compiler/Mapper/Object/Data/HierarchicalWithEnumParentInput.php

@@ -8,7 +8,7 @@
 #[Discriminator(
     'type',
     mapping: [
-        HierarchicalWithEnumType::ChildOne->value => HierarchicalWithEnumChildInput::class,
+        'childOne' => HierarchicalWithEnumChildInput::class,
     ],
 )]
 abstract class HierarchicalWithEnumParentInput

tests/Compiler/MapperFactory/Data/AnimalInput.php

@@ -7,8 +7,8 @@
 #[Discriminator(
     'type',
     mapping: [
-        AnimalType::Cat->value => AnimalCatInput::class,
-        AnimalType::Dog->value => AnimalDogInput::class,
+        'cat' => AnimalCatInput::class,
+        'dog' => AnimalDogInput::class,
     ],
 )]
 abstract class AnimalInput