fix: enhance React imports in LLM panel component #16282 (#16283)

web/app/components/workflow/nodes/llm/panel.tsx

@@ -1,5 +1,5 @@
 import type { FC } from 'react'
-import React from 'react'
+import React, { useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
 import MemoryConfig from '../_base/components/memory-config'
 import VarReferencePicker from '../_base/components/variable/var-reference-picker'