Duplicated "iOS Build" step from CircleCI to Buildkite

[mokagio]

WIP

---

To test:

PR submission checklist:

• I have considered adding unit tests where possible.
• I have considered if this change warrants user-facing release notes more info and have added them to RELEASE-NOTES.txt if necessary.

[peril-wordpress-mobile]

Wanna run full suite of Android and iOS UI tests? Click here and 'Approve' CI job!

[peril-wordpress-mobile]

Wanna run full suite of Android and iOS UI tests? Click here and 'Approve' CI job!

[peril-wordpress-mobile]

Wanna run full suite of Android and iOS UI tests? Click here and 'Approve' CI job!

[mokagio]

Getting some

HTTP Status: 500
{
	"message": "An unknown server-side error occurred while processing the command.
       Original error: Could not extract Info.plist from 'GutenbergDemo.app':
          Plist file doesn't exist:
            '/var/folders/3n/z0_2p7gn03q5x5mt40c4lj1m0000kr/T/202386-3093-1uz43f4.nw69/GutenbergDemo.app/Info.plist'"
}

[mokagio]

Got to the bottom of it, I think.

If you look at the Buildkite logs when zipping the GutenbergDemo.app package, there is indeed no Info.plist. Compare them to the CircleCI ones, and you'll see that they do have the file.

I believe this is happening because the previous step, npm run core test:e2e:build-app:ios failed silently. See logs here because of the provisioning profile issue already noticed in WordPress/gutenberg#54079

[mokagio]

Okay, so the reason was a dumb forgetting that piping output will lose exit code unless explicitly specified.

That is why the build step didn't fail despite the script failing, therefore resulting in the tests running but without access to a fully built .app.

As for the reason why the script, that is the xcodebuild call, failed, by looking at the Buildkite logs once more we can see that there is no iPhone 13 Simulator available so we go back to the code signing process looking using the Mac machine as the target, which fails. I'll fix that next, once established that the set -o pipefail does its job.

[mokagio]

Happy to say that the test annotation and Slack reporting worked fine :)

[mokagio]

Closing in favor of #6179, which took these changes minus all the Git noise.