fix: some build errors and warnings caused by useless code

src/components/KeyValueList.tsx

@@ -1,4 +1,4 @@
-import React, { useEffect, useState, useRef } from 'react';
+import React, { useEffect, useState } from 'react';
 import { Row, Col, Input, Button } from 'antd';
 import { PlusOutlined, DeleteOutlined } from '@ant-design/icons';
 import './KeyValueList.css';