argo-workflows create --only-json doesn't export the cron workflow configuration

[leogargu]

When a flow uses the @schedule decorator, running argo-workflows create deploys two things:

• An Argo workflow template for the flow
• An Argo cron workflow that triggers the flow on schedule

However, when running argo-workflows create --only-json, only the Argo Workflow Template for the flow gets generated, the schedule configuration is lost.