* Add dithering to the `Speech2TextFeatureExtractor` API.
- in kaldi : 4a8b7f6732/src/feat/feature-window.cc (L145)
- with dithering without a seed, the features become non-deterministic due
to small Gaussian noise added to the audio (i.e. 2 runs lead to little
different outputs)
* update the PR
- add dithering also for WhisperFeatureExtractor
- not adding to Wav2Vec2FeatureExtractor (no FBANK computation)
* add unit-tests for dithering, fix docstrings
* ruff
* utils/check_copies.py --fix_and_overwrite
* update code, add seed to unit-test
* adding explanation of dithering