Clean up service bootstrap in open-telemetry example

Signed-off-by: Moritz Lang <[email protected]>

Author: slashmo

Examples/open-telemetry/Sources/Example/Example.swift

@@ -57,8 +57,7 @@ struct Example {
         }
 
         var app = Application(router: router)
-        app.addServices(observability)
-        app.addServices(valkeyClient)
+        app.addServices(observability, valkeyClient)
 
         try await app.runService()
     }