Render lang attribute for email language preference

[aduth]

🛠 Summary of changes

Updates account page email language preference to render lang attribute when showing content in a language other than the page's current language, following #10808 and to satisfy WCAG SC 3.1.2 Language of Parts.

Previously: #10808 (review)

📜 Testing Plan

1. Go to http://localhost:3000
2. Sign in
3. On account dashboard, change email language preference to a language other than English (or conversely, change the current page language to a language other than English)
4. Activate screen reader
5. Navigate to the text value for current email language preference
6. Observe that screen reader announces language value in that language

👀 Screenshots

(You may need to unmute video player for audio to play)

Before:

before.mp4

After:

after.mp4