Code suggestions not being rendered properly in preview mode

The suggestion gets rendered properly when the comment is posted but it should also work on the "Preview" tab.

This worked before and is a recent regression

Reproduction steps

This can be reproduced on .com.

  1. On an MR, start a diff note and write a suggestion

    Screenshot_2026-01-08_at_17.14.03

  2. Open the preview tab

    Screenshot_2026-01-08_at_17.14.10