Fix strict pnpm type resolution for @headlessui/react

[raashish1601]

Summary

• add optional @types/react and @types/react-dom peers for @headlessui/react so strict pnpm installs know about the React type packages the declarations rely on
• keep useFloatingReference() typed against @floating-ui/react's public ReferenceType export instead of leaking @floating-ui/react-dom into the published declarations

Testing

px prettier --write packages/@headlessui-react/package.json packages/@headlessui-react/src/internal/floating.tsx`n-
px tsc --emitDeclarationOnly --outDir dist (in packages/@headlessui-react)

• corepack pnpm exec tsc --noEmit in a strict-pnpm repro after installing the packed local tarball

Closes #3865

[vercel]

@raashish1601 is attempting to deploy a commit to the Tailwind Labs Team on Vercel.

A member of the Team first needs to authorize it.