[CI/CD][bugfix]fix: error argument to loads has incompatible type (#21223)

Signed-off-by: Sungjae Lee <33976427+llsj14@users.noreply.github.com>
Signed-off-by: Sungjae Lee <sung-jae.lee@navercorp.com>

vllm/engine/arg_utils.py

@@ -1266,8 +1266,8 @@ class EngineArgs:
         )
 
         observability_config = ObservabilityConfig(
-            show_hidden_metrics_for_version=self.
-            show_hidden_metrics_for_version,
+            show_hidden_metrics_for_version=(
+                self.show_hidden_metrics_for_version),
             otlp_traces_endpoint=self.otlp_traces_endpoint,
             collect_detailed_traces=self.collect_detailed_traces,
         )