Suggest or nudge with Danger when changes are only in `ee/` and `spec/`

What does this MR do?

If only ee/ and spec/ are changed, it could be a warning that some EE-specific behaviors are tested in FOSS tests, which might cause a problem once EE is synced to gitlab-foss.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides
• Separation of EE specific content

Closes #219263 (closed).