[feature request] make it possible to disable jedi

[ds-cbo]

I am using Zuban as LSP for the same goals Jedi has in python-lsp-server (Completions, Definitions, Hover, References, Signature Help, and Symbols), but would still like to use for example black and isort through python-lsp-server and its plugins. Sadly, that setup now gets me double completions and references everywhere because of the base Jedi

It would be nice if I could disable Jedi and only use the plugins I enable