next.js

eaaa1937 - Always transform styled-jsx for rsc and error with client-only condition (#43386)

Always transform styled-jsx for rsc and error with client-only condition (#43386) Previously we stopped transform css-in-js libraries for RSC server layer because it's not encouraged to use them in server components but client components for saving the bytes of RSC payload. We can detect styled-jsx usage on RSC server layer and error with `client-only` condition, but since it was not transformed properly so it's not erroring properly. In the future, once styled-components and emotion have `client-only` depepdency integrated so we can re-enable the transform for them on server layer ## Bug - [ ] Related issues linked using `fixes #number` - [x] Integration tests added - [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)