Add trailing newline to step2_hidden.yaml

pre-commit's end-of-file-fixer hook tripped on the
agent's authored YAML (no final \n). Fixing so the
code-quality CI check passes.

Author: ChenhanYu

tools/launcher/examples/Qwen/Qwen3-8B/step2_hidden.yaml

@@ -37,4 +37,4 @@ pipeline:
       nodes: 1
       ntasks_per_node: 8
       gpus_per_node: 8
-      container: nvcr.io/nvidia/tensorrt-llm/release:1.2.0
+      container: nvcr.io/nvidia/tensorrt-llm/release:1.2.0