fix (timers): Voice event task creation.

src/modules/pomodoro/cog.py

@@ -184,14 +184,14 @@ class TimerCog(LionCog):
             joining = self.get_channel_timer(after.channel.id) if after.channel else None
 
             tasks = []
-            if leaving:
-                tasks.append(leaving.update_status_card())
+            if leaving is not None:
+                tasks.append(asyncio.create_task(leaving.update_status_card()))
             if joining is not None:
                 joining.last_seen[member.id] = utc_now()
                 if not joining.running and joining.auto_restart:
-                    tasks.append(joining.start())
+                    tasks.append(asyncio.create_task(joining.start()))
                 else:
-                    tasks.append(joining.update_status_card())
+                    tasks.append(asyncio.create_task(joining.update_status_card()))
 
             if tasks:
                 try:

src/modules/pomodoro/timer.py

@@ -447,6 +447,7 @@ class Timer:
 
                 with open(alert_file, 'rb') as audio_stream:
                     finished = asyncio.Event()
+                    loop = asyncio.get_event_loop()
 
                     def voice_callback(error):
                         if error:
@@ -456,7 +457,7 @@ class Timer:
                                 logger.exception(
                                     f"Callback exception occured while playing voice alert for timer {self!r}"
                                 )
-                        finished.set()
+                        loop.call_soon_threadsafe(finished.set)
 
                     voice_client.play(discord.PCMAudio(audio_stream), after=voice_callback)