chore(build): remove the translation_of metadata

[yin1999]

Summary

The "translation_of" metadata is used to present the en-US slug when we use a "localized" slug for a translated document. We have only used it in the past.

For now, we use the same slug for localized documents as for en-US documents, and we have removed the "translation_of" metadata from translated-content repo (check the search result, finished in mdn/translated-content#7412). It's time to get rid of this metadata key.

Solution

Search through the source code, and remove all the reference of this metadata key:

1. remove it from the type definition.
2. remove it from "documentData1.json", and update the urls/slugs (according to the "translation_of" fields).
3. remove it from testing raw documents (under "testing/translated-content/files/" tree)
4. remove the usage of it from "build/index.ts" (used to generate other_translation when the building document is from translation content and the slug is "localized" (the translations cannot be generated))
5. remove the "redundant-translations" tool, which is used to detect documents that have the same "translation_of" metadata key

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Screenshots

Check if the other translations can be generated without the translation_of metadata.

Before

After

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How did you test this change?

[fiji-flo]

Thanks for cleaning up and apologies for the delay.