Fix notification for approved_merge_request_email

What does this MR do and why?

Fixes a regression issue with email template for MR approval. This is probably related to changes merged in !90793 (diffs).

Todo: fix specs / pipeline

Screenshots or screen recordings

before	after

How to set up and validate locally

Verify this at gdk.test:3000/rails/mailers/notify/approved_merge_request_email

MR acceptance checklist

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