Make GITLAB_FEATURES in build_spec compatible with EE

What does this MR do?

Right now this fails in EE MR https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4393 since the EE codebase defaults to having a starter license which means there are features in this value. This seems to be incompatible with the statement that tests should behave the same in CE as EE but I think that since there is a before on all EE specs creating a starter license it unfortunately does not behave that way.

This is needed for #40994 (closed) and fixes the failing specs in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4393

Are there points in the code the reviewer needs to double check?

It is possible that we could make some changes in EE so that all tests default to not having a license as is described in the ee features guidelines, however I think that will likely be a big change that possibly affects many tests. I'd like to investigate that soon but for now I think this is necessary to get the EE part of this work merged.

Why was this MR needed?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?

Closes #40994 (closed)