[Pipeline] Add zero shot audio classificatoin pipeline
# What does this PR do?
Add the `zero_shot_audio_classification_pipeline`  for the `CLAP` models. See #21370 
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_21600). All of your documentation changes will be reflected on that endpoint.<|||||>LGTM. I'm confused by the error in tests which doesn't seem linked to this PR.<|||||>LGTM ! 