Add Support for Attaching Docker Volumes

[OmanDominik]

Proposed Feature: Introduce a python.docker.volumes configuration option to allow users to specify volumes in the form of mappings, e.g., host_path:container_path. For example:

python { docker { image = "python:3.9" volumes = ["/path/on/host:/path/in/container", "/another/host/path:/another/container/path"] } }