Support for React 19

[csvan]

I am well aware that Enzyme has yet to officially support React 17 (https://github.com/enzymejs/enzyme/issues/2429) and 18 (https://github.com/enzymejs/enzyme/issues/2524), but adding this issue to track support of React 19.

React 19 was officially released on December 5, 2024

https://react.dev/blog/2024/12/05/react-19