backport: fix(turbo): sassOptions silenceDeprecations was not overwritten with user options (#74005)
Backports:
- https://github.com/vercel/next.js/pull/73937
Co-authored-by: Jiwon Choi <devjiwonchoi@gmail.com>
Co-authored-by: Donny/강동윤 <kdy1997.dev@gmail.com>