Pls Fix AttributeError: module 'torch.testing' has no attribute 'assert_close'

after setup the pytorchVideo then test
there is a bug

```
======================================================================
ERROR: test_video_transform_factory (test_transforms.TestTransforms)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/aalmadani/mywork/clean/pytorchvideo/pytorchvideo/tests/test_transforms.py", line 1087, in test_video_transform_factory
torch.testing.assert_close(
AttributeError: module 'torch.testing' has no attribute 'assert_close'

```

Start with pytorchvideo/tests/test_transforms.py at line 1087 and run test_video_transform_factory to reproduce the reported AttributeError. Check the surrounding test and the installed PyTorch testing API to determine the supported assertion path; done means this test runs without the reported error.

Written by the indexing model from the issue text.