[examples] Replace wrong import with @mui/material/styles (#43236)

examples/material-ui-vite-ts/src/main.tsx

@@ -1,6 +1,6 @@
 import * as React from 'react';
 import * as ReactDOM from 'react-dom/client';
-import { ThemeProvider } from '@emotion/react';
+import { ThemeProvider } from '@mui/material/styles';
 import { CssBaseline } from '@mui/material';
 import theme from './theme';
 import App from './App';