vendors/execa.js/setKillTimeout
var setKillTimeout = (kill, signal, options, killResult) => {
  if (!shouldForceKill(signal, options, killResult)) {
    return;
  }
  const timeout = getForceKillAfterTimeout(options);
  const t = setTimeout(() => {
    kill("SIGKILL");
  }, timeout);
  if (t.unref) {
    t.unref();
  }
};