Add commandline arguments to flake8 call

[buhtz]

My eglot-pylsp-setup do use flake8.

I do use this piece of code somewhere from your docu to activate flake8.

              ;; the correct format is described here: https://joaotavora.github.io/eglot/#Eglot-Variables
              ;; the configuration to setup flake8 here: https://github.com/python-lsp/python-lsp-server#configuration
              '((:pyls . (:plugins (:mccabe (:enabled :json-false))))
                (:pylsp . (:plugins (:mccabe (:enabled :json-false)
                                             :pycodestyle (:enabled :json-false)
                                             :pyflakes (:enabled :json-false)
                                             :flake8 (:enabled t)
                                             :rope_autoimport (:enabled :json-false))
                                    :configurationSources ["flake8"]))

I would like to add arguments to flake8 without using a config file (.flake8) inside my repository.
Calling it on command line I would like to do flake8 --builtins="_".

Can I do this somewho in my Emacs init file eglot-pylsp-config?