fix(Wav2Vec2ForCTC): torch export (#34023)
* fix(Wav2Vec2ForCTC): torch export
Resolves the issue described in #34022 by implementing the
masking of the hidden states using an elementwise multiplication
rather than indexing with assignment.
The torch.export functionality seems to mark the tensor as frozen
even though the update is legal.
This change is a workaround for now to allow the export of the
model as a FxGraph. Further investigation is required to find
the real solution in pytorch.
* [run-slow] hubert, unispeech, unispeech_sat, wav2vec2
