Add gitlab-ui styles to the haml views in the ci_cd settings dir

What does this MR do?

This changes the button styles from the haml views in the app/views/groups/settings/ci_cd directory

#231197 (closed)

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content