[ci skip] update screenshot png of demo page
[ci skip] update screenshot png of demo page

cyber-dojo/runner_stateless,cyber-dojo/runner_stateless,cyber-dojo/runner,cyber-dojo/runner_stateless,cyber-dojo/runner,cyber-dojo/runner_stateless,cyber-dojo/runner_stateless,cyber-dojo/runner_stateless,cyber-dojo/runner_stateless