Process::start with TimeoutCancellation stops running process on Windows

I'm not sure if this is a bug or intentional. Could you help me figure it out please?

The cancellation parameter isn't described in PHPDOC, but I assume it's intended to cancel the startup procedure, not the process itself.

The behavior is different on Linux and Windows. Which is confusing.

Here is a test script to demonstrate the issue.

<?php

include_once __DIR__.'/vendor/autoload.php';

use Amp\Process\Process;
use Amp\TimeoutCancellation;
use function Amp\delay;

$cmd = PHP_OS_FAMILY === 'Windows' ? 'ping -n 100 127.0.0.1' : 'sleep 100';

echo PHP_OS_FAMILY.', php '.PHP_VERSION."\n";
echo $cmd."\n";

$process = Process::start($cmd, cancellation: new TimeoutCancellation(3, "Startup timeout"));

echo $process->isRunning() ? "running\n" : "stopped\n";

foreach (range(1, 5) as $x) {
	delay(1);
	echo $process->isRunning() ? "running\n" : "stopped\n";
}

$process->kill();

Windows

Windows, php 8.3.14
ping -n 100 127.0.0.1
running
running
running
stopped
stopped
stopped

Linux

Linux, php 8.3.27
sleep 100
running
running
running
running
running
running

Start with the supplied Process::start test script and run it on both Windows and Linux to reproduce the different cancellation behavior. Inspect the Process::start cancellation handling, then establish whether cancellation should stop only startup or also the process; done means the intended behavior is consistent across platforms and the cancellation parameter is documented.