Investigate whether React 19 will be compatible with ICDS React components

[GCHQ-Developer-112]

Summary

Ensure that React 19 is compatible with ICDS React components. Check for breaking changes and any potential issues that arise if React 19 is used with ICDS React components

[evenstensberg]

I think the best way to do this is to just update to v19 and then see if any regression happens.

[evenstensberg]

FYI I just ran ncu -u (npm-check-updates) and it seems some packages havent bumped the react dependencies yet. So that means you probably need to wait sometime to be able to smoothly update the deps that again rely on the correct react version.

While doing this, you should update all dependencies (in both monorepo and root package level).

[ad9242]

duplicate here: #2939

[evenstensberg]

Summary

I've tried updating deps again ncu -u in the react package. If you run:

1. ncu -u
2. npm i --legacy-peer-deps

The installations doesnt cause an error, but there are two problems:

1 (cypress doesnt support react v19 yet)

2

There's a change in how you declare refs in v18 -> v19 (https://react.dev/blog/2024/12/05/react-19#ref-as-a-prop)

[GCHQ-Developer-530]

Closed - remaining work will be done in #3158 and remaining Storybook work done after #3135