Useful way to provide backward compatible widget backgrounds

view+background.swift

extension View {
    @ViewBuilder
    func widgetBackground<V>(@ViewBuilder content: () -> V) -> some View where V : View {
        if #available(macOSApplicationExtension 14.0, iOSApplicationExtension 17.0, *) {
            containerBackground(for: .widget) {
                content()
            }
        } else {
            background {
                content()
            }
        }
    }
}