primitives(Flex): Event handlers for Flex as="form" are not typed properly

[wlee221]

Before creating a new issue, please confirm:

• I have searched for duplicate or closed issues and discussions.
• I have tried disabling all browser extensions or using a different browser
• I have tried deleting the node_modules folder and reinstalling my dependencies
• I have read the guide for submitting bug reports.

On which framework/platform are you having an issue?

React

Which UI component?

Other

How is your app built?

CRA (TS)

What browsers are you seeing the problem on?

Firefox, Chrome, Safari, Microsoft Edge

Please describe your bug.

onSubmit handler isn' typed properly on Flex as="form" element.

Its onSubmit is typed as FormEventHandler<HTMLDivElement>, whereas it should be FormEventHandler<HTMLFormElement>.

What's the expected behaviour?

(see above)

Help us reproduce the bug!

https://codesandbox.io/s/recursing-bird-eewc0q?file=/src/App.tsx

Code Snippet

No response

Additional information and screenshots

No response

[zchenwei]

This should be fixed in 5.x release.