As can be seen from the first round of testing in PR #15864, trying to update Puppeteer beyond version `19.0.0` completely breaks testing in Firefox. Curiously it does work locally when the `--noChrome` flag is being used, so it seems to be an issue with running tests in both Chrome *and* Firefox in parallel.

We need to fix this, likely by making some adjustments to our test-suite, such that we don't get "stuck" on an older version of Puppeteer without being able to update. (A temporary work-around could also be to disable testing in Chrome.)

function sync(removeTmp) {
    console.log("  Updating ref/ ... ");
    testUtils.copySubtreeSync(refsTmpDir, refsDir);
    if (removeTmp) {
      testUtils.removeDirSync(refsTmpDir);
    }
    console.log("done");
  }
  if (options.noPrompts) {
    sync(false); 
    return;
  }
  const reader = readline.createInterface(process.stdin, process.stdout);
  reader.question(
    "Would you like to update the master copy in ref/? [yn] ",
    function (answer) {
      if (answer.toLowerCase() === "y") {
        sync(true);
      } else {
        console.log("  OK, not updating.");
      }
      reader.close();
    }
  );
}
function examineRefImages() {