AO3-6726 separate languages used for works from other uses of languages

[Cesium-Ice]

Pull Request Checklist

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• Have you read the contributing guidelines?
• Have you added tests for any changed functionality?
• Have you added the Jira issue number
  as the first thing in your pull request title (e.g. AO3-1234 Fix thing)
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Issue

https://otwarchive.atlassian.net/browse/AO3-6726

Purpose

What does this PR do?

Testing Instructions

How can the Archive's QA team verify that this is working as you intended?

If you have a Jira account with access, please update or comment on the issue
with any new or missing testing instructions instead.

References

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Credit

What name and pronouns should we use to credit you in the Archive of Our Own's Release Notes?

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field on your Jira profile, so we can assign you the issues you're working on.

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