Inline RSpec/FilePath rubocop rule

What

Inlines a rubocop rule from gitlab-styles, to avoid specifying the paths there.

Needed because we needed to add a new EE exception

Related

https://gitlab.com/gitlab-org/gitlab-styles/merge_requests/14/diffs#note_107160167 https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/5622/diffs#note_107160575

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides