Remove instantiation of unused http client session

These examples don't make any HTTP requests with `session` so there
doesn't seem be a need to create one in the first place. Probably a
copy-paste from a previous example.

examples/foundational/01b-livekit-audio.py

@@ -77,37 +77,36 @@ async def configure_livekit():
 
 
 async def main():
-    async with aiohttp.ClientSession() as session:
-        (url, token, room_name) = await configure_livekit()
+    (url, token, room_name) = await configure_livekit()
 
-        transport = LiveKitTransport(
-            url=url,
-            token=token,
-            room_name=room_name,
-            params=LiveKitParams(audio_out_enabled=True),
-        )
+    transport = LiveKitTransport(
+        url=url,
+        token=token,
+        room_name=room_name,
+        params=LiveKitParams(audio_out_enabled=True),
+    )
 
-        tts = CartesiaTTSService(
-            api_key=os.getenv("CARTESIA_API_KEY"),
-            voice_id="71a7ad14-091c-4e8e-a314-022ece01c121",  # British Reading Lady
-        )
+    tts = CartesiaTTSService(
+        api_key=os.getenv("CARTESIA_API_KEY"),
+        voice_id="71a7ad14-091c-4e8e-a314-022ece01c121",  # British Reading Lady
+    )
 
-        runner = PipelineRunner()
+    runner = PipelineRunner()
 
-        task = PipelineTask(Pipeline([tts, transport.output()]))
+    task = PipelineTask(Pipeline([tts, transport.output()]))
 
-        # Register an event handler so we can play the audio when the
-        # participant joins.
-        @transport.event_handler("on_first_participant_joined")
-        async def on_first_participant_joined(transport, participant_id):
-            await asyncio.sleep(1)
-            await task.queue_frame(
-                TextFrame(
-                    "Hello there! How are you doing today? Would you like to talk about the weather?"
-                )
+    # Register an event handler so we can play the audio when the
+    # participant joins.
+    @transport.event_handler("on_first_participant_joined")
+    async def on_first_participant_joined(transport, participant_id):
+        await asyncio.sleep(1)
+        await task.queue_frame(
+            TextFrame(
+                "Hello there! How are you doing today? Would you like to talk about the weather?"
             )
+        )
 
-        await runner.run(task)
+    await runner.run(task)
 
 
 if __name__ == "__main__":