Update audio processing state: next_index=63

processing_audio_state.json

@@ -63,6 +63,7 @@
     "audio/week04 08 ik ribbon spine squash stretch color coding.wav": "failed",
     "audio/week04 07 ik ribbon spine squash stretch with volume preservation.wav": "failed",
     "audio/week04 06 ik ribbon spine cleanup and skinning.wav": "failed",
-    "audio/week04 05 ik ribbon spine even surfaced distribution.wav": "failed"
+    "audio/week04 05 ik ribbon spine even surfaced distribution.wav": "failed",
+    "audio/week04 04 ik ribbon spine start.wav": "processing"
   }
 }