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.