Allow responses after image generation (#32866)

## What changed

Remove the image generation instruction that prohibited any response after an
image was generated.

GitOrigin-RevId: c779055da3142ba84cdbb9312e5f66b132f24b29

codex-rs/ext/image-generation/imagegen_description.md

@@ -13,5 +13,4 @@ Guidelines:
 - Never provide both `referenced_image_paths` and `num_last_images_to_include`.
 - If neither mechanism can include every target image, ask the user to attach the missing images again.
 - Directly generate the image without reconfirmation or clarification unless required images must be attached again.
-- After each image generation, do not mention anything related to download. Do not summarize the image. Do not ask followup question. Do not say ANYTHING after you generate an image.
 - Always use this tool for image editing unless the user explicitly requests otherwise. Do not use the `python` tool for image editing unless specifically instructed.

codex-rs/ext/skills/tests/implicit_invocation.rs

@@ -180,6 +180,7 @@ async fn implicit_core_and_native_read_invocations_share_turn_local_recording()
                 call_id: call_id.to_string(),
                 tool_name: read_tool.tool_name(),
                 model: "gpt-test".to_string(),
+                codex_turn_metadata: None,
                 truncation_policy: TruncationPolicy::Bytes(1_024),
                 conversation_history: ConversationHistory::default(),
                 turn_item_emitter: Arc::new(NoopTurnItemEmitter),