[BugFix] Fix Wan2.2-VACE-Fun cache and serving lifecycle (#4667)

Signed-off-by: Ianniu <985683179yzy@gmail.com>
Signed-off-by: david6666666 <530634352@qq.com>
Co-authored-by: Ianniu <985683179yzy@gmail.com>

tests/diffusion/models/wan2_2/test_wan22_vace_pipeline.py

@@ -14,6 +14,7 @@ from vllm_omni.diffusion.models.wan2_2.pipeline_wan2_2_vace import (
     create_vace_transformer_from_config,
     get_wan22_vace_pre_process_func,
 )
+from vllm_omni.diffusion.models.wan2_2.wan2_2_vace_transformer import WanVACETransformer3DModel
 
 pytestmark = [pytest.mark.core_model, pytest.mark.cpu, pytest.mark.diffusion]
 
@@ -93,6 +94,10 @@ def test_create_vace_transformer_from_config_maps_vace_specific_keys(monkeypatch
     }
 
 
+def test_vace_transformer_layerwise_offloads_conditioning_blocks() -> None:
+    assert WanVACETransformer3DModel._layerwise_offload_blocks_attrs == ["vace_blocks", "blocks"]
+
+
 def test_vace_prepare_masks_encodes_spatial_stride_and_reference_padding() -> None:
     pipeline = _make_vace_pipeline()
     mask = torch.ones(1, 3, 5, 16, 16)