Revert "[core] add optional status_code to error events (#6865)" (#6955)

This reverts commit c2ec477d93.

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codex-rs/exec/src/event_processor_with_human_output.rs

@@ -161,7 +161,7 @@ impl EventProcessor for EventProcessorWithHumanOutput {
     fn process_event(&mut self, event: Event) -> CodexStatus {
         let Event { id: _, msg } = event;
         match msg {
-            EventMsg::Error(ErrorEvent { message, .. }) => {
+            EventMsg::Error(ErrorEvent { message }) => {
                 let prefix = "ERROR:".style(self.red);
                 ts_msg!(self, "{prefix} {message}");
             }
@@ -221,7 +221,7 @@ impl EventProcessor for EventProcessorWithHumanOutput {
             EventMsg::BackgroundEvent(BackgroundEventEvent { message }) => {
                 ts_msg!(self, "{}", message.style(self.dimmed));
             }
-            EventMsg::StreamError(StreamErrorEvent { message, .. }) => {
+            EventMsg::StreamError(StreamErrorEvent { message }) => {
                 ts_msg!(self, "{}", message.style(self.dimmed));
             }
             EventMsg::TaskStarted(_) => {