The issue is that the python file saved under DBFS not as a workspace notebook.
When you given /artifacts/client-state vector/0.0.0/bootstrap.py, the workspace will search the notebook(python file in this case) under the folder that under Workspace tab in the UI. If you prefer, this way, you can either create a folder under Workspace tab or upload to any exist folder and then import your python file there.
The folder "/dbfs/artifacts/client-state-vector/0.0.0/bootstrap.py" is only valid to be used in cluster. The /dbfs is mount point that each cluster has and allow the cluster to access the DBFS filesystem as local file.