Remove PayerErrors dictionary from MDN

[queengooborg]

This PR removes the PayerErrors dictionary from the MDN web docs to go along with its removal in BCD, see mdn/browser-compat-data#12768. None of these pages were linked on other pages or referenced in any way, so this PR simply removes the pages.

[github-actions]

Preview URLs

• https://pr9711.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/Payment_Request_API

Flaws

None! 🎉

External URLs

URL: /en-US/docs/Web/API/Payment_Request_API
Title: Payment Request API
on GitHub

• https://developer.samsung.com/internet/android/web-payments-integration-guide.html (1 time)
• https://developers.google.com/pay/api/web/guides/paymentrequest/tutorial (1 time)
• https://github.com/w3c/payment-request-info/wiki/FAQ (1 time)
• https://w3c.github.io/payment-method-id/ (1 time)
• https://w3c.github.io/payment-request/ (1 time)
• https://webkit.org/blog/8182/introducing-the-payment-request-api-for-apple-pay/ (1 time)

[hamishwillee]

Thanks very much!

FYI @Rumyra some work that won't need to be done to tidy the Payments API :-)