[Misc] Support WorkerWrapperBase and CustomPipeline for Diffusion Worker (#764)

Signed-off-by: knlnguyen1802 <knlnguyen1802@gmail.com>

tests/diffusion/test_diffusion_worker.py

@@ -36,7 +36,7 @@ def mock_od_config():
 @pytest.fixture
 def mock_gpu_worker(mock_od_config):
     """Create a DiffusionWorker with mocked initialization."""
-    with patch.object(DiffusionWorker, "init_device"):
+    with patch.object(DiffusionWorker, "init_device"), patch.object(DiffusionWorker, "load_model"):
         worker = DiffusionWorker(local_rank=0, rank=0, od_config=mock_od_config)
         # Mock the model_runner with pipeline
         worker.model_runner = Mock()