Bump torch>=1.8.0 and torchvision>=0.9.0 (#11970)

requirements.txt

@@ -12,8 +12,8 @@ PyYAML>=5.3.1
 requests>=2.23.0
 scipy>=1.4.1
 thop>=0.1.1  # FLOPs computation
-torch>=1.7.0  # see https://pytorch.org/get-started/locally (recommended)
-torchvision>=0.8.1
+torch>=1.8.0  # see https://pytorch.org/get-started/locally (recommended)
+torchvision>=0.9.0
 tqdm>=4.64.0
 ultralytics>=8.0.147
 # protobuf<=3.20.1  # https://github.com/ultralytics/yolov5/issues/8012