Fix incorrect casing

Author: AJenbo

src/Testing/PHPUnit/InitContainerBeforeDataProviderSubscriber.php

@@ -16,7 +16,7 @@ public function notify(DataProviderMethodCalled $event): void
 	{
 		$testClassName = $event->testMethod()->className();
 
-		if (!is_a($testClassName, PhpStanTestCase::class, true)) {
+		if (!is_a($testClassName, PHPStanTestCase::class, true)) {
 			return;
 		}
 

src/Testing/PHPUnit/InitContainerBeforeTestSubscriber.php

@@ -22,7 +22,7 @@ public function notify(PreparationStarted $event): void
 
 		$testClassName = $test->className();
 
-		if (!is_a($testClassName, PhpStanTestCase::class, true)) {
+		if (!is_a($testClassName, PHPStanTestCase::class, true)) {
 			return;
 		}