docs(whisper): cast input features to model dtype in AutoModel example (#49837)
openai/whisper-large-v3-turbo loads in float16 by default, while the
feature extractor emits float32, so the example raised
"Input type (float) and bias type (c10::Half) should be the same".
Fixes #47805
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>