Update to sourmash 4.0

[olgabot]

Is your feature request related to a problem? Please describe

The newest Sourmash 4.0 release is much faster (many operations moved from Python to Rust), and includes a new sourmash sketch command that allows for separately making DNA and protein sketches. This is super helpful as the parameters for protein sketches vs DNA sketches are different. Additionally, it now has native support for amino acid k-mer sizes! E.g. I'd like to do:

• DNA nucleotide k-mer size=21
• Protein amino acid k-mer size=10
• Dayhoff amino acid k-mer size=17

Right now, this has to be done all in one command, and all alphabets get k-merized at each k-size, which doesn't really make sense. Dayhoff with nucleotide k=21 has far too low information content to be usable. While DNA has 4^21 options at ksize=21, since Dayhoff is an amino acid alphabet, the k-mer size is really 21/7, so 6^7 << 4^21 and doesn't have enough information to distinguish between cell types. It's basically random at that point.

https://github.com/dib-lab/sourmash/blob/5e66db91e62353de2b79f23cd198ef6f5c5544d1/doc/sourmash-sketch.md

Describe the solution you'd like

Add Sourmash 4.0: https://anaconda.org/bioconda/sourmash
(released ~1 week ago)

Describe alternatives you've considered

Could stay with current Sourmash but this is the future!!

Additional context

NA