chore: fix test

Author: timurbazhirov

src/py/mat3ra/code/entity.py

@@ -85,7 +85,7 @@ def id(self, id: str) -> None:
     def slug(self) -> str:
         return self.prop("slug", "")
 
-    def get_as_entity_reference(self, by_id_only: bool = False) -> dict[str, str]:
+    def get_as_entity_reference(self, by_id_only: bool = False) -> Dict[str, str]:
         if by_id_only:
             return {"_id": self.id}
         else: