Add audioop-lts for Python 3.13 compatibility

The audioop module was removed in Python 3.13, causing gradio/pydub to fail.
audioop-lts provides the missing module.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

hf-space/requirements.txt

@@ -5,3 +5,4 @@ numpy
 requests
 einops
 timm
+audioop-lts