[serve] deflake windows test (ray-project#59771)

test_controller was timing out
```
[2025-12-30T19:04:59Z] //python/ray/serve/tests:test_controller                                TIMEOUT in 3 out of 3 in 60.1s
```

Signed-off-by: abrar <abrar@anyscale.com>
Signed-off-by: peterxcli <peterxcli@gmail.com>

Author: abrarsheikh

python/ray/serve/tests/BUILD.bazel

@@ -74,7 +74,6 @@ py_test_module_list(
         "test_advanced.py",
         "test_cluster_node_info_cache.py",
         "test_constructor_failure.py",
-        "test_controller.py",
         "test_deployment_version.py",
         "test_enable_task_events.py",
         "test_expected_versions.py",
@@ -107,6 +106,7 @@ py_test_module_list(
         "test_batching.py",
         "test_callback.py",
         "test_cluster.py",
+        "test_controller.py",
         "test_controller_recovery.py",
         "test_deploy_2.py",
         "test_deployment_scheduler.py",

python/ray/serve/tests/test_deploy_2.py

@@ -123,7 +123,7 @@ async def __call__(self):
     with ThreadPoolExecutor() as pool:
         # Send the first request, it should block for the result
         first_blocking_fut = pool.submit(functools.partial(httpx.get, url, timeout=100))
-        time.sleep(1)
+        wait_for_condition(lambda: ray.get(s.cur_num_waiters.remote()) == 1)
         assert not first_blocking_fut.done()
 
         # Send more requests, these should be queued in handle.
@@ -134,8 +134,7 @@ async def __call__(self):
             pool.submit(functools.partial(httpx.get, url, timeout=0.5))
             for _ in range(3)
         ]
-        time.sleep(1)
-        assert all(f.done() for f in rest_blocking_futs)
+        wait_for_condition(lambda: all(f.done() for f in rest_blocking_futs))
 
         # Now unblock the first request.
         ray.get(s.send.remote())