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.)

console.log("All regression tests passed.");
    }
    var runtime = (Date.now() - startTime) / 1000;
    console.log("Runtime was " + runtime.toFixed(1) + " seconds");
    if (options.statsFile) {
      fs.writeFileSync(options.statsFile, JSON.stringify(stats, null, 2));
    }
    if (masterMode) {
      if (numEqFailures + numEqNoSnapshot > 0) {
        console.log();
        console.log("Some eq tests failed or didn't have snapshots.");
        console.log("Checking to see if master references can be updated...");
        if (numFatalFailures > 0) {
          console.log("  No.  Some non-eq tests failed.");
        } else {
          console.log(
            "  Yes!  The references in tmp/ can be synced with ref/."
          );
          updateRefImages();
        }
      }
    } else if (showRefImages && numEqFailures > 0) {
      console.log();
      console.log(
        `Starting reftest harness to examine ${numEqFailures} eq test failures.`
      );
      examineRefImages();
    }
  }
  function setup() {