Remove unused imports after manual review (#3229)

* remove unused imports after manual review

* Update torchvision/datasets/voc.py
Co-authored-by: Vasilis Vryniotis <datumbox@users.noreply.github.com>

* remove two more instances
Co-authored-by: Ben Weinstein <benweinstein@Bens-MacBook-Pro.local>
Co-authored-by: Vasilis Vryniotis <datumbox@users.noreply.github.com>

references/classification/train_quantization.py

 import datetime
 import os
 import time
-import sys
 import copy
 
 import torch

references/detection/train.py

@@ -23,7 +23,6 @@ import time
 
 import torch
 import torch.utils.data
-from torch import nn
 import torchvision
 import torchvision.models.detection
 import torchvision.models.detection.mask_rcnn

references/detection/transforms.py

 import random
-import torch
 
 from torchvision.transforms import functional as F
 

references/similarity/model.py

-import torch
 import torch.nn as nn
 import torchvision.models as models
 

torchvision/datasets/cityscapes.py

 import json
 import os
 from collections import namedtuple
-import zipfile
 from typing import Any, Callable, Dict, List, Optional, Union, Tuple
 
 from .utils import extract_archive, verify_str_arg, iterable_to_str

torchvision/datasets/omniglot.py

 from PIL import Image
 from os.path import join
-import os
 from typing import Any, Callable, List, Optional, Tuple
 from .vision import VisionDataset
 from .utils import download_and_extract_archive, check_integrity, list_dir, list_files

torchvision/datasets/ucf101.py

-import glob
 import os
 
 from .utils import list_dir

torchvision/datasets/utils.py

@@ -2,7 +2,6 @@ import os
 import os.path
 import hashlib
 import gzip
-import errno
 import tarfile
 from typing import Any, Callable, List, Iterable, Optional, TypeVar
 import zipfile

torchvision/datasets/video_utils.py

@@ -8,7 +8,6 @@ import torch
 from torchvision.io import (
     _probe_video_from_file,
     _read_video_from_file,
-    _read_video_timestamps_from_file,
     read_video,
     read_video_timestamps,
 )

torchvision/datasets/voc.py

@@ -4,8 +4,8 @@ import collections
 from .vision import VisionDataset
 import xml.etree.ElementTree as ET
 from PIL import Image
-from typing import Any, Callable, Dict, List, Optional, Tuple, Union
-from .utils import download_url, check_integrity, verify_str_arg
+from typing import Any, Callable, Dict, Optional, Tuple
+from .utils import download_url, verify_str_arg
 
 DATASET_YEAR_DICT = {
     '2012': {

torchvision/models/detection/mask_rcnn.py

 from collections import OrderedDict
 
-import torch
 from torch import nn
-import torch.nn.functional as F
 
-from torchvision.ops import misc as misc_nn_ops
 from torchvision.ops import MultiScaleRoIAlign
 
 from ._utils import overwrite_eps

torchvision/models/detection/transform.py

-import random
 import math
 import torch
 from torch import nn, Tensor

torchvision/models/video/resnet.py

-import torch
 import torch.nn as nn
 
 from ..utils import load_state_dict_from_url