text: Title: [Docs] Remove redundant CI when docs merged into main
  Body: ### Checklist
  
  - [x] 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.
  - [x] 2. Please use English, otherwise it will be closed.
  
  ### Motivation
  
  <img width="640" alt="Image" src="https://github.com/user-attachments/assets/4e7bc601-683f-494f-8d47-c3c80f71e309" />
  
  The execute notebook CI is to test the correctness of PRs. If one CI is merged into main, it should not be triggered, but just use execute-and-deploy. We should fix our CI workflow.
  
  ### Related resources
  
  _No response_