add dev dependencies to pyproject.toml ?

[drammock]

To make it easy for others to develop / remix / build this installer locally, I think we should add either a Makefile recipe, something like this:

build-environment:
    @conda create -n sp-installer "python=3.11" conda-build conda-verify constructor joblib threadpoolctl && \
    conda activate sp-installer

... or put a dev section in project.optional_dependencies of pyproject.toml that will install the necessary build deps.

Originally posted by @drammock in #3 (review)