Build/782 parallel cypress webpack 5

[jps]

#782

What

• Background - why this is needed our cypress tests are now taking > 10 mins to run. I looked at doing this through the CircleCI orb but cypress has been a bit scummy and made it so you can only use the feature if you sign up for their cloud service.
• What did you do - cypress-parallel came out as the best way for us to proceed at this point in time ^1
• Bonus WebPack upgrade included as I couldn't run the e2e tests locally likely because I am using WSL, this should improve build speeds a bit and does open the way for rspack which @JohnTParsons has been looking at.
• What should the reviewers expect? faster tests and builds

The following image shows some of the tunings that I looked at as part of this work. unfortunately, cypress-parallel becomes flakey at higher worker counts. It's not immediately clear what the issue is here.

^1 because of the limitation / bug in cypress-parallel it may be beneficial to take a look at sorry-cypress again at some point in the future so we can better utilize large instance sizes in CirlceIC and increased benefit. Setting this up will be less simple than cypress-parallel as it requires it's orchestration service to be running. I do have an example of running this locally available in this commit 72cd996

I have done:

• Written unit tests against changes
• Written functional tests against the component and/or NewsKit site
• Updated relevant documentation

I have tested manually:

• The feature's functionality is working as expected on Chrome, Firefox, Safari and Edge
• The screen reader reads and flows through the elements as expected.
• There are no new errors in the browser console coming from this PR.
• When visual test is not added, it renders correctly on different browsers and mobile viewports (Safari, Firefox, small mobile viewport, tablet)
• The Playground feature is working as expected

Before:

After:

Who should review this PR:

How to test:

[pp-serviceaccount]

You can preview these changes on:
Documentation Site: http://ncu-newskit-docs-pr.s3-website-eu-west-1.amazonaws.com/782-parallel-cypress-webpack-5
Storybook: http://ncu-newskit-docs-pr.s3-website-eu-west-1.amazonaws.com/782-parallel-cypress-webpack-5/storybook

[JohnTParsons]

I presume it fails without that wait? Perhaps it could wait for something to appear in the DOM instead?

[jps]

I would expect it to get increasingly flakey the lower the number gets, It was in there from before, I'll spin it out into a separate task to take a look at as would like to get this merged. The Impact of this will be a bit less than 2mins given it's now parallelized. so possibly not as high priority as say compared to the rspack work.

[mstuartf]

I remember @baburay23 looked into this when there was a bug and added intercepts for all the api calls. So I'm not sure what the wait is waiting for. So it might be that this can just be deleted. Did you have issues without it?

[JohnTParsons]

I've noticed that package.json contains "@types/webpack": "^4.4.34"
This could be upgraded to version 5.28.1 (in this PR or a future one)

[jps]

I've noticed that package.json contains "@types/webpack": "^4.4.34" This could be upgraded to version 5.28.1 (in this PR or a future one)

addressed in #804