Gracefully handle docker not being installed

```
File "/home/james/projects/opendata.studio/datapackages/bindfit-datapackage/.venv/lib64/python3.12/site-packages/docker/api/client.py", line 230, in _retrieve_server_version
    raise DockerException(
docker.errors.DockerException: Error while fetching server API version: ('Connection aborted.', FileNotFoundError(2, 'No such file or directory'))
```