fix: alter Arxiv to ArXiv #918 (#1705)

### What problem does this PR solve?
fix: alter Arxiv to ArXiv #918
### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/flow/canvas/node/index.tsx

@@ -14,7 +14,7 @@ import NodePopover from './popover';
 const ZeroGapOperators = [
   Operator.RewriteQuestion,
   Operator.KeywordExtract,
-  Operator.Arxiv,
+  Operator.ArXiv,
 ];
 
 export function RagNode({