Improve user turn stop timing by triggering timeout from VAD stop

Refactor TranscriptionUserTurnStopStrategy and TurnAnalyzerUserTurnStopStrategy
to use VADUserStoppedSpeakingFrame as the ground truth for when speech ended,
rather than triggering timeouts from transcription frames.

tests/test_user_turn_controller.py

@@ -18,11 +18,13 @@ from pipecat.frames.frames import (
 from pipecat.turns.user_start.min_words_user_turn_start_strategy import (
     MinWordsUserTurnStartStrategy,
 )
+from pipecat.turns.user_stop import SpeechTimeoutUserTurnStopStrategy
 from pipecat.turns.user_turn_controller import UserTurnController
 from pipecat.turns.user_turn_strategies import ExternalUserTurnStrategies, UserTurnStrategies
 from pipecat.utils.asyncio.task_manager import TaskManager, TaskManagerParams
 
 USER_TURN_STOP_TIMEOUT = 0.2
+TRANSCRIPTION_TIMEOUT = 0.1
 
 
 class TestUserTurnController(unittest.IsolatedAsyncioTestCase):
@@ -31,7 +33,11 @@ class TestUserTurnController(unittest.IsolatedAsyncioTestCase):
         self.task_manager.setup(TaskManagerParams(loop=asyncio.get_running_loop()))
 
     async def test_default_user_turn_strategies(self):
-        controller = UserTurnController(user_turn_strategies=UserTurnStrategies())
+        controller = UserTurnController(
+            user_turn_strategies=UserTurnStrategies(
+                stop=[SpeechTimeoutUserTurnStopStrategy(user_speech_timeout=TRANSCRIPTION_TIMEOUT)],
+            )
+        )
 
         await controller.setup(self.task_manager)
 
@@ -60,6 +66,8 @@ class TestUserTurnController(unittest.IsolatedAsyncioTestCase):
 
         await controller.process_frame(VADUserStoppedSpeakingFrame())
         self.assertTrue(should_start)
+        # Wait for user_speech_timeout to elapse
+        await asyncio.sleep(TRANSCRIPTION_TIMEOUT + 0.1)
         self.assertTrue(should_stop)
 
     async def test_user_turn_start_reset(self):