text: Title: Add CI for jupyter notebook example `workflow_by_code.ipynb`
  Body: ## 🌟 Feature Description
  <!-- A clear and concise description of the feature proposal -->
  
  
  CI that it can't detect the errors in the report.
  So I think it would be better to add such a check in our CI. (It may be some command like jupyter nbconvert workflow_by_code.ipynb)
  
  Please refer to this comment.
  https://github.com/microsoft/qlib/pull/1267#issuecomment-1230072848
  
  
  ## Motivation
  
  1. Application scenario
  2. Related works (Papers, Github repos etc.):
  3. Any other relevant and important information:
  
  <!-- Please describe why the feature is important. -->
  
  ## Alternatives
  
  <!-- A short description of any alternative solutions or features you've considered. -->
  
  ## Additional Notes
  
  <!-- Add any other context or screenshots about the feature request here. -->