Remove wiki_front_matter FF

What does this MR do and why?

A small MVC for: #353926 (closed) to add the feature by default.

Screenshots or screen recordings

N/A

How to set up and validate locally

N/A

MR acceptance checklist

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

• I have evaluated the MR acceptance checklist for this MR.

.gitlab/ci/rules.gitlab-ci.yml

@@ -167,6 +167,7 @@
 .yaml-lint-patterns: &yaml-lint-patterns
   - ".gitlab-ci.yml"
   - ".gitlab/ci/**/*.yml"
+  - "data/**/*.yml"
   - "lib/gitlab/ci/templates/**/*.yml"
 
 .docs-patterns: &docs-patterns