Update main.py

main.py

@@ -369,7 +369,7 @@ def convert_format(audio_bytes: bytes, from_fmt: str, to_fmt: str) -> bytes:
         audio.export(buf, format=to_fmt)
     return buf.getvalue()
 
-def parse_audio_mime_type(mime_type: str) -> dict[str, int | None]:
+def parse_audio_mime_type(mime_type: str) -> dict[str, int]:
     """Parses bits per sample and rate from an audio MIME type string """
     bits_per_sample = 16
     rate = 24000