Pin python_version to 3.10 to fix audioop removal on Python 3.13

Space was building on Python 3.13, where the stdlib audioop module was
removed (PEP 594); pydub (a gradio dep) imports it, crashing at startup.
Pin to 3.10 to match the original working environment.

README.md

@@ -5,6 +5,7 @@ colorFrom: pink
 colorTo: purple
 sdk: gradio
 sdk_version: 4.44.0
+python_version: "3.10"
 app_file: app.py
 pinned: false
 license: apache-2.0