Add missing --do-not-cache-result CLI option

Author: sebastianbergmann

tests/end-to-end/regression/5771.phpt

@@ -2,6 +2,7 @@
 https://github.com/sebastianbergmann/phpunit/issues/5771
 --FILE--
 <?php declare(strict_types=1);
+$_SERVER['argv'][] = '--do-not-cache-result';
 $_SERVER['argv'][] = '--no-configuration';
 $_SERVER['argv'][] = '--no-output';
 $_SERVER['argv'][] = __DIR__ . '/5771/Issue5771Test.php';