Updating Dockerfile and Compose build config file for ngen-based worker
images (calibration, partitioning, testing, etc.) to utilize ARG sourced
from environment config to control the version of numpy that is
installed.

Updating example for DMOD deployment environment config with section for
numpy, new numpy constraint environmental variable used by worker image
builds, safe default value for new variable, and comments explaining.

Updating project requirements.txt and GUI service requirements file
(python/gui/dependencies.txt) to constrain numpy version consistent with
default used by worker image builds set up in example.env.

Rolling back initial changes in favor of a different approach.

Adding constraints file to ngen (and related) image build to control
numpy and pip versions as needed for compatibility, using this instead
of doing directly within the Dockerfile itself in pip commands.