Replace torch.FloatTensor with torch.Tensor in the model files (#50183)
Type hints and docstrings only, applied uniformly to modular and
generated modeling files, model tests and the modular example fixtures.
Constructor calls (torch.FloatTensor(...)) and .type(torch.FloatTensor)
are left as they are. The two OwlViT functions copied from
loss_for_object_detection are updated together with that file in the
companion PR.
Closes #35003.