add encryptedcontent to functioncalloutput (#23500)

add new `EncryptedContent` variant to `FunctionCallOutputContentItem`
ahead of standalone websearch.

we need to be able to receive and pass encrypted function call output
from the new web search endpoint back to responsesapi, as we cannot
expose direct search results.

codex-rs/tools/src/tool_output.rs

@@ -209,7 +209,8 @@ fn content_items_to_code_mode_result(items: &[FunctionCallOutputContentItem]) ->
                     Some(image_url.clone())
                 }
                 FunctionCallOutputContentItem::InputText { .. }
-                | FunctionCallOutputContentItem::InputImage { .. } => None,
+                | FunctionCallOutputContentItem::InputImage { .. }
+                | FunctionCallOutputContentItem::EncryptedContent { .. } => None,
             })
             .collect::<Vec<_>>()
             .join("\n"),