Add sm_103 (Grace Blackwell) arch support to sglang dependency configuration

[terrykong]

Summary

PR #2134 adds 10.3 (sm_103 / Grace Blackwell / B300) to TORCH_CUDA_ARCH_LIST in docker/Dockerfile, but the same architecture support needs to be propagated to other places in the repo.

Specifically, the sglang dependencies in pyproject.toml (line 219) and any related sglang configuration should also be updated to ensure sm_103 compatibility when running on B300 hardware.

Context

• PR feat: Docker Blackwell / Grace Blackwell container support #2134 added Blackwell/Grace Blackwell container support in the Dockerfile
• The sglang optional dependency group (and potentially other places) may need similar arch-aware updates to fully support B300

Related

• feat: Docker Blackwell / Grace Blackwell container support #2134