[HTTP] Copy array returned by getRoutes (#195647)

## Summary

Small follow up based on
#192675 (comment)

packages/core/http/core-http-router-server-internal/src/router.ts

@@ -240,7 +240,7 @@ export class Router<Context extends RequestHandlerContextBase = RequestHandlerCo
     if (excludeVersionedRoutes) {
       return this.routes.filter((route) => !route.isVersioned);
     }
-    return this.routes;
+    return [...this.routes];
   }
 
   public handleLegacyErrors = wrapErrors;