Yield after create_task to ensure timer tasks are scheduled

Add `await asyncio.sleep(0)` after `create_task()` calls in
UserIdleController, SpeechTimeoutUserTurnStopStrategy,
TurnAnalyzerUserTurnStopStrategy, and UserTurnCompletionLLMServiceMixin
so the event loop schedules the newly created timer tasks before the
caller continues.

src/pipecat/turns/user_idle_controller.py

@@ -143,6 +143,8 @@ class UserIdleController(BaseObject):
             self._idle_timer_expired(),
             f"{self}::idle_timer",
         )
+        # Make sure the task is scheduled.
+        await asyncio.sleep(0)
 
     async def _cancel_idle_timer(self):
         """Cancel the idle timer if running."""

src/pipecat/turns/user_stop/speech_timeout_user_turn_stop_strategy.py

@@ -153,6 +153,8 @@ class SpeechTimeoutUserTurnStopStrategy(BaseUserTurnStopStrategy):
         self._timeout_task = self.task_manager.create_task(
             self._timeout_handler(timeout), f"{self}::_timeout_handler"
         )
+        # Make sure the task is scheduled.
+        await asyncio.sleep(0)
 
     async def _handle_transcription(self, frame: TranscriptionFrame):
         """Handle user transcription."""
@@ -174,6 +176,8 @@ class SpeechTimeoutUserTurnStopStrategy(BaseUserTurnStopStrategy):
             self._timeout_task = self.task_manager.create_task(
                 self._timeout_handler(timeout), f"{self}::_timeout_handler"
             )
+            # Make sure the task is scheduled.
+            await asyncio.sleep(0)
 
     def _calculate_timeout(self) -> float:
         """Calculate the timeout value based on current state.

src/pipecat/turns/user_stop/turn_analyzer_user_turn_stop_strategy.py

@@ -193,6 +193,8 @@ class TurnAnalyzerUserTurnStopStrategy(BaseUserTurnStopStrategy):
         self._timeout_task = self.task_manager.create_task(
             self._timeout_handler(timeout), f"{self}::_timeout_handler"
         )
+        # Make sure the task is scheduled.
+        await asyncio.sleep(0)
 
     async def _handle_transcription(self, frame: TranscriptionFrame):
         """Handle user transcription."""
@@ -217,6 +219,8 @@ class TurnAnalyzerUserTurnStopStrategy(BaseUserTurnStopStrategy):
             self._timeout_task = self.task_manager.create_task(
                 self._timeout_handler(timeout), f"{self}::_timeout_handler"
             )
+            # Make sure the task is scheduled.
+            await asyncio.sleep(0)
 
     async def _handle_prediction_result(self, result: Optional[MetricsData]):
         """Handle a prediction result event from the turn analyzer."""

src/pipecat/turns/user_turn_completion_mixin.py

@@ -254,6 +254,8 @@ class UserTurnCompletionLLMServiceMixin:
             self._incomplete_timeout_handler(incomplete_type, timeout),
             f"_incomplete_timeout_{incomplete_type}",
         )
+        # Make sure the task is scheduled.
+        await asyncio.sleep(0)
 
     async def _cancel_incomplete_timeout(self):
         """Cancel any pending incomplete timeout task."""