Fix doc example: mask_time_indices (numpy) has no attribute 'to' (#15033)
* fix doc example - AttributeError: 'numpy.ndarray' object has no attribute 'to'
* fix more
* Apply suggestions from code review
* Update src/transformers/models/unispeech/modeling_unispeech.py
Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>