image_export.py failed for artifact JupyterConfigFile.

When running processing for test disk, I keep getting Task failure for ```* FileArtifactExtractionTask: image_export.py failed for artifact JupyterConfigFile.```

When enabling debug_logs:
```
2021-09-13 21:40:59,647 [DEBUG] (MainProcess) PID:120696 Starting preprocessing.
2021-09-13 21:41:00,243 [DEBUG] (MainProcess) PID:120696 Preprocessing done.
2021-09-13 21:41:00,244 [DEBUG] (MainProcess) PID:120696 building find specification based on artifacts: JupyterConfigFile
2021-09-13 21:41:00,783 [DEBUG] (MainProcess) PID:120696 building find spec from artifact definition: JupyterConfigFile
2021-09-13 21:41:00,783 [DEBUG] (MainProcess) PID:120696 building find spec from path glob: %%users.homedir%%/.jupyter/jupyter_notebook_config.py
2021-09-13 21:41:00,783 [WARNING] (MainProcess) PID:120696 Unable to build collection filters with error: No valid file system find specifications were built from artifacts.
```

Start with image_export.py and the JupyterConfigFile artifact definition, focusing on the path glob %%users.homedir%%/.jupyter/jupyter_notebook_config.py and the debug log showing invalid filesystem find specifications. Reproduce the failure with debug_logs enabled; done means the artifact produces valid collection filters and the FileArtifactExtractionTask succeeds.

Written by the indexing model from the issue text.