WebImage is not rendered with drawingGroup()

Example code to reproduce:

```swift
struct AsyncImageDemoView: View {
    let url = URL(string: "https://placekitten.com/200/300")
    
    var body: some View {
        if let url {
            Text("URL: \(url)")
            WebImage(url: url)
                .drawingGroup()
        }
    }
}
```