Fix ts warning

Author: fzaninotto

packages/ra-ui-materialui/src/list/ListView.tsx

@@ -1,12 +1,6 @@
 import * as React from 'react';
 import { styled } from '@mui/material/styles';
-import {
-    Children,
-    cloneElement,
-    ReactElement,
-    ReactNode,
-    ElementType,
-} from 'react';
+import { cloneElement, ReactElement, ReactNode, ElementType } from 'react';
 import PropTypes from 'prop-types';
 import { SxProps } from '@mui/system';
 import Card from '@mui/material/Card';