remove unnecessary todos (#8842)

> // todo(aibrahim): why are we passing model here while it can change?

we update it on each turn with `.with_model`

> //TODO(aibrahim): run CI in release mode.

although it's good to have, release builds take double the time tests
take.

> // todo(aibrahim): make this async function

we figured out another way of doing this sync

codex-rs/core/src/codex.rs

@@ -643,7 +643,6 @@ impl Session {
         }
         maybe_push_chat_wire_api_deprecation(&config, &mut post_session_configured_events);
 
-        // todo(aibrahim): why are we passing model here while it can change?
         let otel_manager = OtelManager::new(
             conversation_id,
             session_configuration.model.as_str(),