feat: deprecation warning (#5825)

<img width="955" height="311" alt="Screenshot 2025-10-28 at 14 26 25"
src="https://github.com/user-attachments/assets/99729b3d-3bc9-4503-aab3-8dc919220ab4"
/>

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -290,7 +290,8 @@ async fn run_codex_tool_session_inner(
                     | EventMsg::ItemCompleted(_)
                     | EventMsg::UndoStarted(_)
                     | EventMsg::UndoCompleted(_)
-                    | EventMsg::ExitedReviewMode(_) => {
+                    | EventMsg::ExitedReviewMode(_)
+                    | EventMsg::DeprecationNotice(_) => {
                         // For now, we do not do anything extra for these
                         // events. Note that
                         // send(codex_event_to_notification(&event)) above has