fix syntax error and it pass the test case

app/routers/nodes.py

@@ -1,31 +1,8 @@
 from fastapi import APIRouter
-from app.k8s_client import get_core_client
+from app.k8s_client import fetch_nodes
 
 router = APIRouter(prefix="/nodes", tags=["nodes"])
 
-
 @router.get("/")
-def list_node():
-    v1 = get_core_client()
-    nodes = v1.list_node().items
-    result = []
-    for n in nodes:
-        conditions = {c.type: c.status for c in n.status.conditions}
-        result.append(
-            {
-                "name": n.metadata.name,
-                "ready": conditions.get("Ready") == "True",
-                "cpu_capacity": n.status.capacity.get("cpu"),
-                "memory_capacity": n.status.capacity.get("memory"),
-                "labels": n.metadata.labels,
-                "age_days": _age(n.metadata.creation_timestamp),
-            }
-        )
-    return result
-
-
-def _age(ts) -> int:
-    from datetime import datetime, timezone
-
-    now = datetime.now(timezone.utc)
-    return (now - ts).days
+def list_nodes():
+    return fetch_nodes()