[Model] Add Cache-DiT and CPU offload support for SANA-Video 2B (#5882)

Signed-off-by: cr-gao <gaochenrui@sjtu.edu.cn>
Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>
Co-authored-by: Alicia <115451386+congw729@users.noreply.github.com>

tests/model_tests/diffusion/diff_model_builders.py

@@ -88,7 +88,7 @@ def _build_tiny_sana_video(pipeline_name: str) -> str:
         out_channels=16,
         num_attention_heads=2,
         attention_head_dim=16,
-        num_layers=1,
+        num_layers=2,
         num_cross_attention_heads=2,
         cross_attention_head_dim=16,
         cross_attention_dim=32,