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.)

var numFBFFailures = 0;
  var round0 = results[0],
    round1 = results[1];
  if (round0.length !== round1.length) {
    console.error("round 1 and 2 sizes are different");
  }
  for (var page = 0; page < round1.length; page++) {
    var r0Page = round0[page],
      r1Page = round1[page];
    if (!r0Page) {
      continue;
    }
    if (r0Page.snapshot !== r1Page.snapshot) {
      
      
      
      
      
      
      
      if (masterMode) {
        console.log(
          "TEST-SKIPPED | forward-back-forward test " +
            task.id +
            " | in " +
            browser +
            " | page" +