DX-104 : NOt used import line

Author: gwendalaubert

tests/Api/UpsertListProductTest.php

@@ -6,7 +6,6 @@
 use donatj\MockWebServer\RequestInfo;
 use donatj\MockWebServer\Response;
 use donatj\MockWebServer\ResponseStack;
-use GuzzleHttp\Promise\Utils;
 use Http\Discovery\Psr17FactoryDiscovery;
 use PHPUnit\Framework\Assert;