Actually disable ai for now (#35327)

Closes https://github.com/zed-industries/zed/issues/35325

* removes Supermaven actions
* removes copilot-related action
* stops re-enabling edit predictions when disabled

Release Notes:

- N/A

crates/editor/src/editor.rs

@@ -56,7 +56,7 @@ use aho_corasick::AhoCorasick;
 use anyhow::{Context as _, Result, anyhow};
 use blink_manager::BlinkManager;
 use buffer_diff::DiffHunkStatus;
-use client::{Collaborator, ParticipantIndex};
+use client::{Collaborator, DisableAiSettings, ParticipantIndex};
 use clock::{AGENT_REPLICA_ID, ReplicaId};
 use collections::{BTreeMap, HashMap, HashSet, VecDeque};
 use convert_case::{Case, Casing};
@@ -7048,7 +7048,7 @@ impl Editor {
     }
 
     pub fn update_edit_prediction_settings(&mut self, cx: &mut Context<Self>) {
-        if self.edit_prediction_provider.is_none() {
+        if self.edit_prediction_provider.is_none() || DisableAiSettings::get_global(cx).disable_ai {
             self.edit_prediction_settings = EditPredictionSettings::Disabled;
         } else {
             let selection = self.selections.newest_anchor();