fix(sdk): preserve queued events on stream close

Signed-off-by: Lanre Shittu <136805224+Shizoqua@users.noreply.github.com>

nanobot/nanobot.py

@@ -302,7 +302,7 @@ class Nanobot:
                 ))
                 raise
             finally:
-                emitter.close()
+                await emitter.close()
 
         task = asyncio.create_task(_run())
         return RunStream(task, queue)

nanobot/sdk/streaming.py

@@ -158,15 +158,11 @@ class SDKStreamEmitter:
             resuming=resuming,
         ))
 
-    def close(self) -> None:
+    async def close(self) -> None:
         if self._closed:
             return
         self._closed = True
-        if self._queue.full():
-            with suppress(asyncio.QueueEmpty):
-                self._queue.get_nowait()
-        with suppress(asyncio.QueueFull):
-            self._queue.put_nowait(_STREAM_SENTINEL)
+        await self._queue.put(_STREAM_SENTINEL)
 
 
 class SDKStreamingHook(AgentHook):