torchvision.transforms.functional import error fix for torchvision 0.17

[HaiderSultanArc]

[IlyesBenAmara]

Please approve this PR

[tomy128]

I think this should be :

try:
    from torchvision.transforms.functional_tensor import rgb_to_grayscale
except ModuleNotFoundError:
    from torchvision.transforms.functional import rgb_to_grayscale

to make it more compatible with older torchvision before we confirm to drop the older supports❓