Revert "fix: handle sessionStorage retrieval and setGraphData in GraphVisualization component"

This reverts commit a6e360e.

Author: yashbhesaniya

Project/frontend/src/components/Graph/index_visjs.tsx

@@ -229,17 +229,12 @@ const GraphVisualization: React.FC = () => {
 
   useEffect(() => {
     const fetchGraphData = async () => {
-      if (sessionStorage.getItem(fileId)) {
-        setGraphData(JSON.parse(sessionStorage.getItem(fileId) as string));
-        setIsLoading(false);
-        return;
       try {
         const response = await fetch(
           `${import.meta.env.VITE_BACKEND_HOST}${VISUALIZE_API_PATH.replace(':fileId', fileId)}`,
         );
         const data = await response.json();
         setGraphData(data);
-        sessionStorage.setItem(fileId, JSON.stringify(data));
 
         // Get the list of unique topics
         const uniqueTopics = Array.from(