Add retry for flaky tests in CI (#4755)

test/srt/test_metrics.py

@@ -7,11 +7,12 @@ from sglang.test.test_utils import (
     DEFAULT_SMALL_MODEL_NAME_FOR_TEST,
     DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
     DEFAULT_URL_FOR_TEST,
+    CustomTestCase,
     popen_launch_server,
 )
 
 
-class TestEnableMetrics(unittest.TestCase):
+class TestEnableMetrics(CustomTestCase):
     def test_metrics_enabled(self):
         """Test that metrics endpoint returns data when enabled"""
         process = popen_launch_server(