Fix missing FrozenDict import in before_denoise.py

Author: akshan-main

src/diffusers/modular_pipelines/hunyuan_video1_5/before_denoise.py

@@ -17,6 +17,7 @@
 import numpy as np
 import torch
 
+from ...configuration_utils import FrozenDict
 from ...models import HunyuanVideo15Transformer3DModel
 from ...schedulers import FlowMatchEulerDiscreteScheduler
 from ...utils import logging