Remove unused import in FakeClient test

Remove unused Contributte\Http\Client\Response import

Author: claude

tests/cases/Client/FakeClient.phpt

@@ -6,7 +6,6 @@
 
 use Contributte\Http\Client\FakeClient;
 use Contributte\Http\Client\Request;
-use Contributte\Http\Client\Response;
 use Tester\Assert;
 
 require_once __DIR__ . '/../../bootstrap.php';