Initial plink, tskit and Python API support

0.1.6 2025-05-23

• Initial Python API support for VCF and tskit one-shot conversion. Format conversion is done using the functions bio2zarr.vcf.convert and bio2zarr.tskit.convert.

• Initial version of supported plink2zarr (#390, #344, #382)

• Initial version of tskit2zarr (#232)

• Make format-specific dependencies optional (#385)

• Remove bed_reader dependency (#397, #400)

• Change default number of worker processes to zero (#404) to simplify
  debugging

Breaking changes

• Remove explicit sample, contig and filter lists from the schema. Existing ICFs will need to be recreated. (#343)

• Add dimensions and default compressor and filter settings to the schema. (#361)

• Various changes to existing experimental plink encoding (#390)