fix(emails): Update Mozilla address in SubPlat email footers

[xlisachan]

Because

• FXA-14150 updated only the copies in libs, but SubPlat still renders from auth-server

This pull request

• Updates the address in auth-server

Issue that this pull request solves

Closes: FXA-14437

Checklist

Put an x in the boxes that apply

• My commit is GPG signed.
• If applicable, I have modified or added tests which pass locally.
• I have added necessary documentation (if appropriate).
• I have verified that my changes render correctly in RTL (if appropriate).
• I have manually reviewed all AI generated code.