fix numpy import error after tensor2vid refactor in huggingface#6626

Author: a-r-r-o-w

src/diffusers/pipelines/animatediff/pipeline_animatediff.py

@@ -16,6 +16,7 @@
 import math
 from typing import Any, Callable, Dict, List, Optional, Tuple, Union
 
+import numpy as np
 import torch
 import torch.fft as fft
 from transformers import CLIPImageProcessor, CLIPTextModel, CLIPTokenizer, CLIPVisionModelWithProjection