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 numEqFailures = 0;
  for (var page = 0; page < pageResults.length; page++) {
    if (!pageResults[page]) {
      continue;
    }
    const pageResult = pageResults[page];
    let testSnapshot = pageResult.snapshot;
    if (testSnapshot && testSnapshot.startsWith("data:image/png;base64,")) {
      testSnapshot = Buffer.from(testSnapshot.substring(22), "base64");
    } else {
      console.error("Valid snapshot was not found.");
    }
    var refSnapshot = null;
    var eq = false;
    var refPath = path.join(refSnapshotDir, page + 1 + ".png");
    if (!fs.existsSync(refPath)) {
      numEqNoSnapshot++;
      if (!masterMode) {
        console.log("WARNING: no reference snapshot " + refPath);
      }
    } else {
      refSnapshot = fs.readFileSync(refPath);
      eq = refSnapshot.toString("hex") === testSnapshot.toString("hex");
      if (!eq) {
        console.log(
          "TEST-UNEXPECTED-FAIL | " +
            taskType +
            " " +
            taskId +
            " | in " +