Rework dependencies and how pytest is run

[philvarner]

What I'm changing

Previously, all of the dependencies across every workspace were installed and then the tests run. This is bad because packages can be used in code and pass tests even though the dependency is not correcly defined in the workspace's pyproject.toml.

How I did it

• refactored the workspace pyproject.toml's to have dev dependencies necessary to run pytest
• created a test running script to install only the dependencies for each workspace and run their tests.

Checklist

• Tests pass: uv run pytest
• Checks pass: uv run pre-commit run --all-files
• CHANGELOG is updated (if necessary)