[chore] update to new torchvision API in models as well

[felixT2K]

This PR:

• same as done for object detection update to new torchvision API

[codecov]

Codecov Report

Merging #1291 (a7e324e) into main (3deac68) will decrease coverage by 0.01%.
Report is 2 commits behind head on main.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1291      +/-   ##
==========================================
- Coverage   95.78%   95.78%   -0.01%     
==========================================
  Files         154      154              
  Lines        6903     6902       -1     
==========================================
- Hits         6612     6611       -1     
  Misses        291      291              

Flag	Coverage Δ
unittests	95.78% <100.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
doctr/models/classification/mobilenet/pytorch.py	100.00% <100.00%> (ø)
doctr/models/classification/resnet/pytorch.py	100.00% <100.00%> (ø)
doctr/models/classification/vgg/pytorch.py	100.00% <100.00%> (ø)
...s/detection/differentiable_binarization/pytorch.py	97.77% <100.00%> (-0.02%)	⬇️

... and 1 file with indirect coverage changes