Add `decoder_kwargs` to send to LM on asr pipeline.
Author: Narsil
Pull request: yes

# What does this PR do?

Fixes #15484

Linked to https://github.com/g8a9/transformers/commit/1f25864edf0319a9984b3051b420b86e287d949b

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Fixes # (issue)


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Comments:
_The documentation is not available anymore as the PR was closed or merged._

> Thanks for adding this feature. Should we maybe add @g8a9 as a co-author here?

Nice catch ! Done.