refactor(web): replace native useContext with use in shared components 🤖🤖🤖

[Jholly2008]

Summary

This PR contributes a small non-overlapping batch for #25193.

• replace remaining React native useContext calls with use in three shared base components
• keep behavior unchanged
• avoid touching use-context-selector usage

Scope

• web/app/components/base/carousel/index.tsx
• web/app/components/base/pagination/pagination.tsx
• web/app/components/base/portal-to-follow-elem/index.tsx

Validation

• pnpm exec vp test run app/components/base/carousel/__tests__/index.spec.tsx app/components/base/pagination/__tests__/pagination.spec.tsx app/components/base/portal-to-follow-elem/__tests__/index.spec.tsx
• pnpm run lint:ci app/components/base/carousel/index.tsx app/components/base/pagination/pagination.tsx app/components/base/portal-to-follow-elem/index.tsx
• pnpm run type-check
• pnpm run lint:tss

fixes #25193