Switch widget has unexpected color on the selected handle/thumb when hovering

### Steps to reproduce

Is it a bug if when hovering a Switch with the mouse the while element ("the physical switch") completely disappears on MacOS? I can understand the switch can change color while hovering over it but not completely make the white element disapear.

### Expected results

I expect the switch to keep the white element visible (the color can change)

### Actual results

the white element disappears when overring

### Code sample

Code sample

```dart
[Paste your code here]
```

### Screenshots or Video

Screenshots / Video demonstration

[Upload media here]

### Logs

Logs

```console
[Paste your logs here]
```

### Flutter Doctor output

Doctor output

```console
[Paste your output here]
```