Fix double brackets being linkified in wiki markdown

What does this MR do?

Solves #18725 (closed)

Are there points in the code the reviewer needs to double check?

Not sure.

Why was this MR needed?

It is impossible to include certain types of text in code blocks (both single-backtick and triple-backtick) in wiki markdown. Certain filetypes are heavily impacted by this, such as:

• gitlab runner config .toml files

• bash scripts

Screenshots (if relevant)

N/A

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

#18725 (closed)