Package handling

[ggmarshall]

At the moment snakemake is installed in its own mamba env when making a prodenv which is then used by each of the production cycles. Instead we could move to snakemake being in its own venv so different prod cycles can use different snakemake versions and extra packages can be installed such as pylegendmeta for snakemake to use outside the container. This could be handled by a modern package handler like uv (which would also handle the venv) thoughts @gipert ?

@Yuan-Ru-Lin

[gipert]

I think it's a good idea, also because Snakemake is now on PyPI.