[PHPUnit12] Add fixture reproducing AllowMockObjects false positive on ConstraintValidatorTestCase

Refs rectorphp/rector#9650

Author: akankov

rules-tests/PHPUnit120/Rector/Class_/AllowMockObjectsWhereParentClassRector/Fixture/skip_constraint_validator_test_case.php.inc

@@ -0,0 +1,10 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\PHPUnit120\Rector\Class_\AllowMockObjectsWhereParentClassRector\Fixture;
+
+use Symfony\Component\Validator\Test\ConstraintValidatorTestCase;
+
+final class SkipConstraintValidatorTestCase extends ConstraintValidatorTestCase
+{
+    private \PHPUnit\Framework\MockObject\MockObject $someMock;
+}