fix(app): remove redundant Arc wrapper around PrometheusHandle

Actix-web's Data<T> extractor expects T to implement Clone,
so PrometheusHandle (which is Clone) does not need to be
wrapped in Arc. The Arc type mismatch caused /metrics to
return 500.

apps/app/src/main.rs

@@ -86,8 +86,7 @@ async fn main() -> anyhow::Result<()> {
     };
 
     let prometheus_handle = install_recorder();
-    let prometheus_handle_arc = std::sync::Arc::new(prometheus_handle);
-    let prometheus_handle_data = web::Data::new(prometheus_handle_arc.clone());
+    let prometheus_handle_data = web::Data::new(prometheus_handle.clone());
 
     let http_metrics = std::sync::Arc::new(HttpMetrics::new());
     let http_snapshot: HttpSnapshotGuard = std::sync::Arc::new(std::sync::RwLock::new(