CI/CD: built-in and light-sandbox steps record their result immediately

An undoes or hot-spots step, a gate, or a machine: light step now shows its result in the console as soon as it finishes, instead of when the check's other jobs end. Previously such a step stayed "running" until then, and a check whose other jobs waited more than 40 minutes for capacity failed with "undoes sent nothing for 40 minutes" although the step had passed.