chore(redirects): remove retiredLocale parameter

[caugner]

Summary

Problem

We redirect retired locales to en-US with a ?retiredLocale=XX parameter to show a retirement message, but this is no longer useful, as those locales have been retired for more than 1.5 years.

Solution

Remove the retirement message and the retiredLocale parameter.

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How did you test this change?

Ran npm i && npm start in /cloud-function and verified that http://localhost:5100/ar/ redirects to http://localhost:5100/en-US/, not http://localhost:5100/en-US/?retiredLocale=ar.

[fiji-flo]

I'm lacking context. I appears this removes the feature all together. Could we not just remove the redirect for the old retired locales? But keep the code?

[caugner]

I'm lacking context.

This is part of our SEO effort, reducing the number of duplicate URLs.

Could we not just remove the redirect for the old retired locales? But keep the code?

We could just remove the redirect, but if nothing links/redirects to ?retiredLocale=XX anymore, why should we keep the code around? This makes me think we might want to redirect from foo/bar?retiredLocale=XX to foo/bar.