fix: Fix the bug that no Ingress is created for AI routes (higress-group#659)

Author: CH3CHO

backend/sdk/src/main/java/com/alibaba/higress/sdk/service/ai/AiRouteServiceImpl.java

@@ -243,6 +243,7 @@ private void writeAiRouteResources(AiRoute aiRoute) {
         String routeName = buildRouteResourceName(aiRoute.getName());
         Route route = buildRoute(routeName, aiRoute);
         setUpstreams(route, aiRoute.getUpstreams());
+        saveRoute(route);
         writeModelRouterResources(aiRoute.getModelPredicates());
         writeModelMappingResources(routeName, aiRoute.getUpstreams());
         writeAiStatisticsResources(routeName);