ImportError: cannot import name 'vcf2zarr' from 'bio2zarr'

[tomwhite]

See https://github.com/sgkit-dev/sgkit/actions/runs/14435286128/job/40475317044

It looks like sgkit-dev/bio2zarr#339 caused this.

[jeromekelleher]

We're not exporting a stable Python API yet in bio2zarr, but I think we're getting close to a long-term stable interface. I'd suggest just patching up tests here for now to get things working again.

Great to have these tests to catch stuff early!

[jeromekelleher]

xref sgkit-dev/bio2zarr#349