Refactor Archives page to use versions.json

What does this MR do and why?

Refactors the Archives page to pull offline/online version lists from content/versions.json instead of content/_data/versions.yaml. We're moving this logic out of the Nanoc template and into a Vue component.

Instead of adding all the offline versions to versions.json, as they were listed in versions.yaml, we instead create that list from the gitlab-docs project's container registry via the GitLab API. This removes a manual step from the monthly release process.

Closes #1237 (closed), #1171 (closed)

Screenshots, screen recordings, or links to review app

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Configure a local GitLab Docs environment: https://gitlab.com/gitlab-org/gitlab-docs/-/blob/main/doc/setup.md.
2. View the archives page: http://localhost:3000/archives. This should show the same versions as the archives page on the production site.

Merge request acceptance checklist

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