[Router]fix: fix get_load missing api_key (#10385)

sgl-router/tests/cache_aware_backward_compat_test.rs

@@ -18,6 +18,7 @@ fn test_backward_compatibility_with_empty_model_id() {
     // Create workers with empty model_id (simulating existing routers)
     let worker1 = BasicWorkerBuilder::new("http://worker1:8080")
         .worker_type(WorkerType::Regular)
+        .api_key("test_api_key")
         .build();
     // No model_id label - should default to "unknown"
 
@@ -25,6 +26,7 @@ fn test_backward_compatibility_with_empty_model_id() {
     labels2.insert("model_id".to_string(), "unknown".to_string());
     let worker2 = BasicWorkerBuilder::new("http://worker2:8080")
         .worker_type(WorkerType::Regular)
+        .api_key("test_api_key")
         .labels(labels2)
         .build();
 
@@ -59,6 +61,7 @@ fn test_mixed_model_ids() {
     // Create workers with different model_id scenarios
     let worker1 = BasicWorkerBuilder::new("http://worker1:8080")
         .worker_type(WorkerType::Regular)
+        .api_key("test_api_key")
         .build();
     // No model_id label - defaults to "unknown" which goes to "default" tree
 
@@ -67,6 +70,7 @@ fn test_mixed_model_ids() {
     let worker2 = BasicWorkerBuilder::new("http://worker2:8080")
         .worker_type(WorkerType::Regular)
         .labels(labels2)
+        .api_key("test_api_key")
         .build();
 
     let mut labels3 = HashMap::new();
@@ -123,10 +127,12 @@ fn test_remove_worker_by_url_backward_compat() {
     let worker1 = BasicWorkerBuilder::new("http://worker1:8080")
         .worker_type(WorkerType::Regular)
         .labels(labels1)
+        .api_key("test_api_key")
         .build();
 
     let worker2 = BasicWorkerBuilder::new("http://worker2:8080")
         .worker_type(WorkerType::Regular)
+        .api_key("test_api_key")
         .build();
     // No model_id label - defaults to "unknown"