setting adjustsImageWhenHighlighted with UIButtonConfiguration

Since adjustsImageWhenHighlighted is deprecated in iOS 15.0, what's the way to set it with UIButtonConfiguration? If I set it directly, I get a message saying "You may customize to replicate this behavior via a configurationUpdateHandler", but what exactly should I be doing to set this in configurationUpdateHandler? Thanks

This is the basics...

Assuming you have "normal" and "highlighted" images:

    // let's use new UIButton.Configuration
    newButton.configuration = .plain()
    
    newButton.configurationUpdateHandler = { button in
        var config = button.configuration
        config?.image = button.isHighlighted ? imgHighlighted : imgNormal
        button.configuration = config
    }

Here's a runnable example, that uses UIGraphicsImageRenderer to create a "darkened" version of the button image "on-the-fly":

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
    
        guard let imgNormal = UIImage(named: "myButtonImage")
        else {
            print("Could not load images!")
            return
        }
        
        // generate a "darkened" version of the image
        let rndr = UIGraphicsImageRenderer(size: imgNormal.size)
        let imgHighlighted = rndr.image { (ctx) in
            imgNormal.draw(at: .zero)
            UIColor.black.withAlphaComponent(0.5).setFill()
            ctx.cgContext.fill(CGRect(origin: .zero, size: imgNormal.size))
        }
        
        let oldButton = UIButton()
        let newButton = UIButton()

        // "standard" button
        oldButton.setImage(imgNormal, for: [])
        // default is .adjustsImageWhenHighlighted = true
        
        // let's use new UIButton.Configuration
        newButton.configuration = .plain()
        
        newButton.configurationUpdateHandler = { button in
            var config = button.configuration
            config?.image = button.isHighlighted ? imgHighlighted : imgNormal
            button.configuration = config
        }
        
        [oldButton, newButton].forEach { b in
            b.translatesAutoresizingMaskIntoConstraints = false
            view.addSubview(b)
        }
        
        let g = view.safeAreaLayoutGuide
        NSLayoutConstraint.activate([
            
            oldButton.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            oldButton.widthAnchor.constraint(equalToConstant: 80.0),
            oldButton.heightAnchor.constraint(equalTo: oldButton.widthAnchor),
            oldButton.centerXAnchor.constraint(equalTo: g.centerXAnchor),
            
            newButton.topAnchor.constraint(equalTo: oldButton.bottomAnchor, constant: 20.0),
            newButton.widthAnchor.constraint(equalTo: oldButton.widthAnchor),
            newButton.heightAnchor.constraint(equalTo: oldButton.widthAnchor),
            newButton.centerXAnchor.constraint(equalTo: g.centerXAnchor),
            
        ])
        
    }
    
}

When you run this, the two buttons should look and function the same.