[wdspec] Fix BiDiSession.add_event_listener to handle several listeners
diff --git a/tools/webdriver/webdriver/bidi/client.py b/tools/webdriver/webdriver/bidi/client.py
index 73bba55..045bc04 100644
--- a/tools/webdriver/webdriver/bidi/client.py
+++ b/tools/webdriver/webdriver/bidi/client.py
@@ -205,7 +205,7 @@
             if not listeners:
                 listeners = self.event_listeners.get(None, [])
             for listener in listeners:
-                await listener(data["method"], data["params"])
+                asyncio.create_task(listener(data["method"], data["params"]))
         else:
             raise ValueError(f"Unexpected message: {data!r}")