Fix edit prediction disablement with "disable_ai": true setting (#35513)

Even after #35327 edit predictions were still being queried and shown
after setting `"disable_ai": true`

Also moves `DisableAiSettings` to the `project` crate so that it gets
included in tests via existing use of `Project::init_settings(cx)`.

Release Notes:

- Fixed `"disable_ai": true` setting disabling edit predictions.

crates/client/src/client.rs

@@ -150,7 +150,6 @@ impl Settings for ProxySettings {
 
 pub fn init_settings(cx: &mut App) {
     TelemetrySettings::register(cx);
-    DisableAiSettings::register(cx);
     ClientSettings::register(cx);
     ProxySettings::register(cx);
 }
@@ -539,33 +538,6 @@ impl settings::Settings for TelemetrySettings {
     }
 }
 
-/// Whether to disable all AI features in Zed.
-///
-/// Default: false
-#[derive(Copy, Clone, Debug)]
-pub struct DisableAiSettings {
-    pub disable_ai: bool,
-}
-
-impl settings::Settings for DisableAiSettings {
-    const KEY: Option<&'static str> = Some("disable_ai");
-
-    type FileContent = Option<bool>;
-
-    fn load(sources: SettingsSources<Self::FileContent>, _: &mut App) -> Result<Self> {
-        Ok(Self {
-            disable_ai: sources
-                .user
-                .or(sources.server)
-                .copied()
-                .flatten()
-                .unwrap_or(sources.default.ok_or_else(Self::missing_default)?),
-        })
-    }
-
-    fn import_from_vscode(_vscode: &settings::VsCodeSettings, _current: &mut Self::FileContent) {}
-}
-
 impl Client {
     pub fn new(
         clock: Arc<dyn SystemClock>,