ultralytics 8.1.26 LoadImagesAndVideos batched inference (#8817)

Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>

tests/test_python.py

@@ -8,6 +8,7 @@ import cv2
 import numpy as np
 import pytest
 import torch
+import yaml
 from PIL import Image
 from torchvision.transforms import ToTensor
 
@@ -169,8 +170,6 @@ def test_track_stream():
 
     Note imgsz=160 required for tracking for higher confidence and better matches
     """
-    import yaml
-
     video_url = "https://ultralytics.com/assets/decelera_portrait_min.mov"
     model = YOLO(MODEL)
     model.track(video_url, imgsz=160, tracker="bytetrack.yaml")