fix: fix misconfigured highlight.js

Description

This MR is a fixes highlighting in Duo Chat introduced in MR yesterday: !1707 (merged)

Thanks @jerasmus for sanity checking the code 🙇 Last night I made a mistake. I was fixing a "security warning" and I "fixed" it by breaking the chat highlighting. When I was testing my MR, I focused on the "no workings" so much that I didn't noticed that the highlighting stopped working.

Related Issues

[VS Code] Add syntax highlighting in code blocks (#1435 - closed)

How has this been tested?

1. Run the extension in development mode
2. Check that chat results have highlighted code blocks (prompt: how to destructure objects in JS)

Screenshots (if appropriate)

What CHANGELOG entry will this MR create?

• fix: Bug fix fixes - a user-facing issue in production - included in changelog
• feature: New feature - a user-facing change which adds functionality - included in changelog
• BREAKING CHANGE: (fix or feature that would cause existing functionality to change) - should bump major version, mentioned in the changelog
• None - other non-user-facing changes