AO3-7612 Update browser page title on the Unassigned Fandoms page

[yujeanshin]

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Issue

https://otwarchive.atlassian.net/browse/AO3-7612

Purpose

This changes the browser page title on the Unassigned Fandoms page from "Unassigned Fandom | Archive of Our Own" to "Unassigned Fandoms | Archive of Our Own". The page heading is left as-is.

Credit

yshin, she/her

[sarken]

Hi, yshin!

Thank you so much for this pull request. Someone will be along to review it soon.

For now, I've updated the Jira issue status to In Review so no one mistakenly creates a duplicate pull request. If you'd like the ability to comment on, assign, and transition issues in the future, you're welcome to create a Jira account! It makes things a bit easier for us on the organizational side if the Full Name on your Jira account either closely matches the name you'd like us to credit in the release notes or includes it in parentheses, e.g. "Nickname (CREDIT NAME)."

Once you've done that (or if you've already done it -- Jira has been unreliable about showing us new accounts in the admin panel lately), you can either reply here or send an email to otw-coders@transformativeworks.org with your account name and email address and we'll set up the permissions for you.

Thanks again for contributing! If you have any questions, you can contact us at the same email address listed above.

[Bilka2]

Thanks for working on this! Could you move this locale string to locales/controllers/en.yml instead? Since we set the locale in the controller we want to define it in the controller related locale file

[Bilka2]

Additionally, could you add a test for this?

[Bilka2]

Thank you!