Fetch dagrun in graph page only when runId is valid. (apache#48729)

Author: tirkarthi

airflow-core/src/airflow/ui/src/layouts/Details/Graph/Graph.tsx

@@ -77,7 +77,7 @@ const edgeTypes = { custom: Edge };
 
 export const Graph = () => {
   const { colorMode = "light" } = useColorMode();
-  const { dagId = "", runId, taskId } = useParams();
+  const { dagId = "", runId = "", taskId } = useParams();
 
   const selectedVersion = useSelectedVersion();
 
@@ -112,7 +112,7 @@ export const Graph = () => {
   const { data: dagRun } = useDagRunServiceGetDagRun(
     {
       dagId,
-      dagRunId: runId ?? "",
+      dagRunId: runId,
     },
     undefined,
     { enabled: runId !== "" },