Run annotation registry only when available

Author: alexander-schranz

tests/bootstrap.php

@@ -11,6 +11,8 @@
 
 require __DIR__ . '/app/TestKernel.php';
 
-AnnotationRegistry::registerLoader([$loader, 'loadClass']);
+if (\class_exists(AnnotationRegistry::class)) {
+    AnnotationRegistry::registerLoader([$loader, 'loadClass']);
+}
 
 return $loader;