[Contracts][HttpClient] Skip tests when zlib's ob_gzhandler() doesn't exist

Author: alexandre-daubois

HttpClient/Test/HttpClientTestCase.php

@@ -25,6 +25,10 @@ abstract class HttpClientTestCase extends TestCase
 {
     public static function setUpBeforeClass(): void
     {
+        if (!function_exists('ob_gzhandler')) {
+            static::markTestSkipped('The "ob_gzhandler" function is not available.');
+        }
+
         TestHttpServer::start();
     }