There is a long list of about:config settings that allow users disable most of the recently introduced AI chatbot features in Firefox but unfortunately not all:

AI Context Menu is still displayed if browser.ml.chat.enabled is set to false:

https://bugzilla.mozilla.org/show_bug.cgi?id=1994785

"Ask an AI Chatbot" context menu is not hidden, even if Machie Learning is disabled:

https://bugzilla.mozilla.org/show_bug.cgi?id=1995119

Mozilla has pretty much ignored this issue for an entire month.