fix(tenant): 按需注册多租户 Job 切面

缺少 xxl-job-core 时跳过 TenantJobAspect 配置，避免未引入
yudao-spring-boot-starter-job 的模块启动时报 NoClassDefFoundError。

Closes https://gitee.com/zhijiantianya/yudao-cloud/issues/IJTOFS

yudao-framework/yudao-spring-boot-starter-biz-tenant/src/main/java/cn/iocoder/yudao/framework/tenant/config/YudaoTenantAutoConfiguration.java

@@ -30,6 +30,7 @@ import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.boot.web.servlet.FilterRegistrationBean;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
 import org.springframework.data.redis.cache.BatchStrategies;
 import org.springframework.data.redis.cache.RedisCacheConfiguration;
@@ -172,13 +173,6 @@ public class YudaoTenantAutoConfiguration {
         return new TenantRocketMQInitializer();
     }
 
-    // ========== Job ==========
-
-    @Bean
-    public TenantJobAspect tenantJobAspect(TenantFrameworkService tenantFrameworkService) {
-        return new TenantJobAspect(tenantFrameworkService);
-    }
-
     // ========== Redis ==========
 
     @Bean
@@ -200,4 +194,17 @@ public class YudaoTenantAutoConfiguration {
         return cacheManager;
     }
 
+    // ========== Job ==========
+
+    @Configuration(proxyBeanMethods = false)
+    @ConditionalOnClass(name = "com.xxl.job.core.context.XxlJobContext")
+    public static class TenantJobConfiguration {
+
+        @Bean
+        public TenantJobAspect tenantJobAspect(TenantFrameworkService tenantFrameworkService) {
+            return new TenantJobAspect(tenantFrameworkService);
+        }
+
+    }
+
 }