onFocusIn and onFocusOut events incorrectly set

[objerke]

Describe the bug
The changing in casing of the onfocusin and onfocusout attributes to onFocusIn and onFocusOut in 4307, introduced in 10.19.7, breaks those types of event listeners.

To Reproduce

1. Go to https://stackblitz.com/edit/vitejs-vite-8tupqq?file=src%2Fmain.tsx
2. Click on the top input field, then click on the next input field
3. See that the top most component does not change from "No focus" to "Has focus". The focusin event listener is never triggered.

Inspecting the element using dev tools, the onFocusIn attrbute creates an event listener for the non standard FocusIn event instead of focusin.

Expected behavior
The same behavior of setting onFocusIn as the previous onfocusin, meaning event listeners for the focusin
since the latter has been removed from the declaration file.

[JoviDeCroock]

Heh, I did not think this would be a thing but 'focusin' in document.createElement('div') evaluates to false hence why this started failing. 😅

[objerke]

The DOM is wonderful at times 😉

Here is a failing test that can be added to events.test.js

it('should support camel-case focus event names', () => {
	render(<div onFocusIn={() => {}} onFocusOut={() => {}} />, scratch);

	expect(proto.addEventListener)
		.to.have.been.calledTwice.and.to.have.been.calledWith('focusin')
		.and.calledWith('focusout');
});

[rschristian]

Looks like the attribute exists in WebKit but not Chrome or FF, do we just need to give them a little push? I've had to do that in the past for FF a couple times.

Edit: Asking as I cannot find any justification for why onfocusin/onfocusout aren't set, unless I'm missing something.

[objerke]

@JoviDeCroock Amazing pace of fixing this and 4221! 💯 🥳