Remove feature flag and use terraform module presenter

What does this MR do and why?

Remove feature flag and use terraform module presenter by default.

The feature flag was enabled on 2025-08-11 on gitlab.com #552336 (comment 2680871223) and no issues were observed so far logs (internal).

References

Introduce terraform module presenter (#552329 - closed)

Screenshots or screen recordings

No.

How to set up and validate locally

Visit the details page of existing terraform module or publish a new one docs. Make sure everything works correctly.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #552329 (closed)