[Feature] Split Docs CI

[zhaochenyang20]

Checklist

• 1. If the issue you raised is not a feature but a question, please raise a discussion at https://github.com/sgl-project/sglang/discussions/new/choose Otherwise, it will be closed.
• 2. Please use English, otherwise it will be closed.

Motivation

Our execute notebook CI now takes over 30mins to run all the notebooks. We should split it into several parts and let multi 1-gpu-runner to compile it. Just like what we do for:

PR Test / unit-test-backend-1-gpu (0-6) (push) Successful in 11m

Related resources

No response