gh15937.phpt does not need to be an online test

We convert the test to use the CLI test server to not require online
availability.

As of PHP 8.3, the test is supposed to fail, because the timeout is too
large.  Since exactly this scenario is already tested by gh16810.phpt,
we drop the test for PHP-8.3 and up.

Closes phpGH-17315.

Author: cmb69

ext/standard/tests/streams/gh15937.phpt

@@ -1,16 +1,22 @@
 --TEST--
 GH-15937 (stream overflow on timeout setting)
---SKIPIF--
-<?php if (getenv("SKIP_ONLINE_TESTS")) die("skip online test"); ?>
 --FILE--
 <?php
+$serverCode = <<<'CODE'
+echo 1;
+CODE;
+
+include __DIR__."/../../../../sapi/cli/tests/php_cli_server.inc";
+php_cli_server_start($serverCode, null, []);
+
+$uri = "http://" . PHP_CLI_SERVER_ADDRESS . '/test';
 $config = [
     'http' => [
         'timeout' => PHP_INT_MAX,
     ],
 ];
 $ctx = stream_context_create($config);
-var_dump(fopen("http://www.example.com", "r", false, $ctx));
+var_dump(fopen("http://" . PHP_CLI_SERVER_ADDRESS . "/test", "r", false, $ctx));
 ?>
 --EXPECTF--
 resource(%d) of type (stream)