Bump terser and next in /djedi-react

Removes [terser](https://github.com/terser/terser). It's no longer used after updating ancestor dependency [next](https://github.com/vercel/next.js). These dependencies need to be updated together.


Removes `terser`

Updates `next` from 8.1.0 to 12.3.1
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v8.1.0...v12.3.1)

---
updated-dependencies:
- dependency-name: terser
  dependency-type: indirect
- dependency-name: next
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>