Remove Starter reference from MR doc

Also, simplify "vice versa"

doc/user/project/merge_requests/merge_request_dependencies.md

@@ -17,9 +17,9 @@ then it cannot be merged until its dependency is itself merged.
 
 NOTE:
 Merge requests dependencies are a **PREMIUM** feature, but this restriction is
-only enforced for the dependent merge request. A merge request in a **FREE** or
-**STARTER** project can be a dependency of a **PREMIUM** merge request, but not
-vice-versa.
+only enforced for the dependent merge request. A merge request in a **FREE**
+project can be a dependency of a **PREMIUM** merge request, but not
+the other way around.
 
 ## Use cases