Revert "Merge branch '353926' into 'master'"

What does this MR do and why?

Revert !81833 (merged) due to the feature causing issues for Wiki Frontmatter. See #359081. For now, we will re-instate the feature flag until we can invest time in fixing the root bug. That way those impacted by the issue have a workaround until then.

Screenshots or screen recordings

N/A

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

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