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/git_ui/src/commit_modal.rs

@@ -1,9 +1,9 @@
 use crate::branch_picker::{self, BranchList};
 use crate::git_panel::{GitPanel, commit_message_editor};
-use client::DisableAiSettings;
 use git::repository::CommitOptions;
 use git::{Amend, Commit, GenerateCommitMessage, Signoff};
 use panel::{panel_button, panel_editor_style};
+use project::DisableAiSettings;
 use settings::Settings;
 use ui::{
     ContextMenu, KeybindingHint, PopoverMenu, PopoverMenuHandle, SplitButton, Tooltip, prelude::*,