[fbsync] Remove unused dynamo import (#8451)

Reviewed By: vmoens

Differential Revision: D60596224

fbshipit-source-id: f74db31da7c828b0d37f200b1f381c5dc9d72144

Author: NicolasHug

torchvision/ops/roi_align.py

@@ -2,7 +2,6 @@
 from typing import List, Union
 
 import torch
-import torch._dynamo
 import torch.fx
 from torch import nn, Tensor
 from torch._dynamo.utils import is_compile_supported