can you confirm if you are using a Vertex AI Workbench instance? As per the error, I believe you are, so please refer to the public documentation below [1].
This error occurs because you can't edit the underlying VM of an instance by using the Google Cloud console or the Compute Engine API.
To edit a Vertex AI Workbench instance's underlying VM, use the projects.locations.instances.patch method in the Notebooks API or the gcloud workbench instances update command in the Google Cloud SDK