I have updated the project template with a new SDC file. Please update your design with the latest changes from the template.
In config.yaml, you need to unset CLOCK_PORT and CLOCK_NET. However, there may still be some issues, so please share your repository.
If your design does not contain any digital logic at all, then you can disable all STA steps. Simply add OpenROAD.STA*: null to substituting_steps in the config.