Update middleware/api_client/src/middleware/api_client/api_client.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: Zalfsten

middleware/api_client/src/middleware/api_client/api_client.py

@@ -484,7 +484,7 @@ def _extract_identifier_from_rocrate(arc_content: dict[str, Any]) -> str | None:
         graph = arc_content.get("@graph")
         if isinstance(graph, list):
             for item in graph:
-                if item.get("@id") == "./":
+                if isinstance(item, dict) and item.get("@id") == "./":
                     identifier = item.get("identifier")
                     if isinstance(identifier, list):
                         identifier = identifier[0] if identifier else None