update CHANGELOG.md and fix formatting

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to **Pipecat** will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+
+- Fixed an issue in `UltravoxSTTService` that caused improper audio processing
+  and incorrect LLM frame output.
+
 ## [0.0.60] - 2025-03-20
 
 ### Added

tests/test_user_idle_processor.py

@@ -86,9 +86,9 @@ class TestUserIdleProcessor(unittest.IsolatedAsyncioTestCase):
             expected_down_frames=expected_down_frames,
         )
 
-        assert (
+        assert not callback_called.is_set(), (
-            not callback_called.is_set()
+            "Idle callback was called even though bot speaking frames reset the timer"
-        ), "Idle callback was called even though bot speaking frames reset the timer"
+        )
 
     async def test_idle_retry_callback(self):
         """Test that retry count increases until user activity resets it."""