fixes [Chips delete button hover style is square, not circular](https://github.com/flutter/flutter/issues/141335)

### Code sample

<details>
<summary>expand to view the code sample</summary> 

```dart
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: RawChip(
            label: const Text('Test'),
            onPressed: null,
            deleteIcon: const Icon(Icons.clear, size: 18),
            onDeleted: () {},
          ),
        ),
      ),
    );
  }
}
```

</details>

### Preview

| Before | After |
| --------------- | --------------- |
| <img src="https://github.com/flutter/flutter/assets/48603081/c5d62c57-97b3-4f94-b83d-df13559ee3a8" /> | <img src="https://github.com/flutter/flutter/assets/48603081/b76edaab-73e0-4aa9-8ca2-127eedd77814"  /> |