Hi! Task runner would not be an appropriate term for this. Since it also defines target based on their modification times. This is what we call a general purpose build system, just like we call Make and Ninja build system.

It can do anything you want if you can provide it with proper shell commands and define targets. This can not only be used for tasks but also for physical building targets that can be built on the machine.

I believe that the project you linked here is itself also a build system and not just a task runner. But again, it uses yaml, which might not be best while defining custom things related to a build system