fix symfony 6.1 partial mocking

Author: dbu

src/Test/EventDispatchingHttpCacheTestCase.php

@@ -72,6 +72,10 @@ protected function getHttpCachePartialMock(array $mockedMethods = null)
  $refOptions->setAccessible(true);
  $refOptions->setValue($mock, $options);
 
+ $surrogate = $refHttpCache->getProperty('surrogate');
+ $surrogate->setAccessible(true);
+ $surrogate->setValue($mock, null);
+
  return $mock;
  }