VCF spec 4.4 introduces the 'P' number for ploidy

[timothymillar]

See the description of the PSL field https://samtools.github.io/hts-specs/VCFv4.4.pdf#subsubsection.1.6.2. This isn't defined explicitly as raised in samtools/hts-specs#705. However, it's implicitly the ploidy of the genotype call ("one for each allele specified in the GT").

This should be added to the VCF-Zarr spec for the ploidy dimension.

[timothymillar]

@tomwhite I can't seem to assign labels etc. here.

[tomwhite]

@tomwhite I can't seem to assign labels etc. here.

I added you to the team so you should be able to now.