Transition to `uv` for Python

[NeuroShepherd]

I would recommend moving away from Conda/Miniforge in favor of the uv package. From the perspective of running the workshops, I believe uv is easier to install and initialize than Miniforge and would lead to fewer start-up problems for the participants.

More broadly, I'd add the following additional reasons for teaching/using uv:

1. Automatically includes a lockfile for dependencies -> improved reproducibility
2. Reduced confusion around pip (Python only installations) vs. Conda (system installations)
3. More general alignment with the Python ecosystem (e.g. use of official pyproject.toml vs. Conda's opinionated environment.yml)