v0.19.0

Major new function - profiling of Caudoviricetes (aka "Caudovirales") phage communities (Lyrebird), thanks to @rzhao-2.

Other changes:

• Update default metapackage to GTDB R226
• admin: Use pixi instead of conda
• Use of diamond v2.1.10 specifically, to avoid segfault issues with diamond v2.1.11
• Clarify non-standard metapackage usage (#220)
• doc: Improve summarise --cluster (#210)

Thanks @rzhao-2 @AroneyS @ilnamkang Phil Hugenholtz @pchaumeil @zackhenny @thepatientwait