fix(components): [tree-v2] add missing icon (#10340)

Co-authored-by: init-qy <953218204@qq.com>

packages/components/tree-v2/src/tree-node.vue

@@ -51,6 +51,7 @@
 <script lang="ts" setup>
 import { computed, inject } from 'vue'
 import ElIcon from '@element-plus/components/icon'
+import { CaretRight } from '@element-plus/icons-vue'
 import ElCheckbox from '@element-plus/components/checkbox'
 import { useNamespace } from '@element-plus/hooks'
 import ElNodeContent from './tree-node-content'
@@ -62,8 +63,6 @@ import {
 } from './virtual-tree'
 import type { CheckboxValueType } from '@element-plus/components/checkbox'
 
-const DEFAULT_ICON = 'caret-right'
-
 defineOptions({
   name: 'ElTreeNode',
 })
@@ -79,7 +78,7 @@ const indent = computed(() => {
 })
 
 const icon = computed(() => {
-  return tree?.props.icon ?? DEFAULT_ICON
+  return tree?.props.icon ?? CaretRight
 })
 
 const handleClick = (e: MouseEvent) => {