Log compaction request bodies (#8676)

We already log request bodies for normal requests, logging for
compaction helps with debugging.

codex-rs/protocol/src/models.rs

@@ -416,7 +416,6 @@ impl Serialize for FunctionCallOutputPayload {
     where
         S: Serializer,
     {
-        tracing::debug!("Function call output payload: {:?}", self);
         if let Some(items) = &self.content_items {
             items.serialize(serializer)
         } else {