fix(ci): fix Next.js E2Es failing since next@canary requires React 19

[wojtekmaj]

What's the problem this PR addresses?

Since next@canary requires React 19, builds were consistently failing.

How did you fix it?

Used React 19 instead. Removed require() bit - didn't test anything particularly IMO and caused type errors.

Checklist

• [x] I have read the Contributing Guide.

• [x] I have set the packages that need to be released for my changes to be effective.

• [x] I will check that all automated PR checks pass before the PR gets reviewed.