Add collaboration_mode override to turns (#9408)

codex-rs/core/tests/suite/truncation.rs

@@ -547,6 +547,7 @@ async fn mcp_image_output_preserves_image_and_no_text_summary() -> Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            collaboration_mode: None,
         })
         .await?;