Ignore specific JS spec files in EESpecificCheck

What does this MR do?

This will make sure we can close https://gitlab.com/gitlab-org/gitlab-ee/issues/3871 at some point, otherwise, people can still add EE-specific files under spec/javascripts/.

What are the relevant issue numbers?

Related to #3871 (closed).

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
• EE specific content should be in the top level /ee folder
• [-] For a paid feature, have we considered GitLab.com plans, how it works for groups, and is there a design for promoting it to users who aren't on the correct plan?