Experiment with adding "latest" to saucelabs config

[Jaifroid]

Experiment to fix #894.

[Jaifroid]

Adding "latest" doesn't seem to solve the issue.

[Jaifroid]

We are getting "InfrastructureError"....

2022-10-08T09:47:21.838Z ERROR webdriver: Request failed with status 500 due to Error: Infrastructure Error -- The Sauce VMs failed to start the browser or device.
For more info, please check https://docs.saucelabs.com/dev/error-messages
2022-10-08T09:47:21.840Z ERROR webdriver: Error: Infrastructure Error -- The Sauce VMs failed to start the browser or device.

[Jaifroid]

Firefox 104 (one before latest) is producing same error. Strange that Firefox 45 can run, but this one can't...

[Jaifroid]

I've found some info on the error we're experiencing: https://docs.saucelabs.com/dev/error-messages/index.html#the-sauce-labs-virtual-machine-failed-to-start-the-browser-or-device. The salient informaiton is:

Causes

• If you're running a Selenium test, this usually means that you're specifying a Selenium version that isn't compatible with the browser/version/OS you selected.
• If you're running an Appium test, this usually means that you're specifying a Appium version that isn't compatible with the browser/version/OS you selected.
• You may have requested an incompatible platform/OS/browser combination.

I assume our issue is the first or last of these bullet points.

[Jaifroid]

I've disabled Firefox latest, which allows us to get past the QUnit tests and on to the end-to-end tests. But now we're getting this persistent failure with both the latest Nightwatch and with the old Nightwatch we used previously:

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (_http_outgoing.js:[47](https://github.com/kiwix/kiwix-js/actions/runs/3392039979/jobs/5637806528#step:7:48)0:11)
    at module.exports.ResponseStream.(anonymous function) [as setHeader] (/home/runner/work/***-js/***-js/node_modules/union/lib/response-stream.js:100:34)
    at Object.exports.(anonymous function) (/home/runner/work/***-js/***-js/node_modules/http-server/lib/core/status-handlers.js:57:7)
    at Readable.stream.on (/home/runner/work/***-js/***-js/node_modules/http-server/lib/core/index.js:339:22)
    at Readable.emit (events.js:198:13)
    at emitErrorNT (internal/streams/destroy.js:91:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:59:3)
    at process._tickCallback (internal/process/next_tick.js:63:19)
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (52) Empty reply from server

[Jaifroid]

Same error with setting headers after they are sent to client persists even with the original configuration minus Firefox latest.

@kelson42 Having exhausted my knowledge about this configuration, and having made 24 commits to this PR tweaking various options, I can only conclude that a fundamental API change has occurred, and that we have a hopelessly out of date configuration here in accessing Sauce Labs. It needs re-building from the ground up, and if I'm going to do that work, it might as well be with a more modern testing infrastructure.

Ideal situation would be to complete #554 -- mossroy and I had discussed using the modern framework vite.js for this, and it has a test suite called https://vitest.dev/. I'd need to look at how it integrates with: 1. SauceLabs and 2. BrowserStack.

But this would be a major job in which I have extremely limited experience.

So maybe if I can get a new config running on BrowserStack by following their step-by-step instructions, which look very thorough, it would be the best compromise for now, along with retaining the QUnit tests that do run successfully in this configuration.

[Jaifroid]

So we can get on with daily business I have had no choice but to disable the end-to-end tests, and to modify the cross-browser QUnit tests so they do not run the latest Firefox. We still have latest Firefox tested in GitHub actions, so this is no real loss, but disabling end-to-end UI testing is a loss, which I hope we can fill with a BrowserStack configuration.

For now, we still have:

• QUnit tests run in Firefox and Chrome headless on GitHub actions, for all contributors.
• QUnit tests run on a suite of Edge (Chromium and Legacy), and Chrome (old and new), and Firefox (old) on SauceLabs.