You can switch to 'Triggered' pipeline in this case.
Next, create a job in workflow and attach a trigger of type 'file arrival' to it. Next add the notebook and cluster to the job. If you're not using DLT, then set cluster timeout minutes to 0, so that your cluster shuts down immediately after it's inactive.
Now, whenever a file will arrive in your landing location, this trigger will go off and will start the cluster which will then run the notebook until it finishes the task.