Fix task_push_notification_config name generation when converting to proto

Author: aneeshgarg

src/a2a/utils/proto_utils.py

@@ -259,7 +259,7 @@ def task_push_notification_config(
         cls, config: types.TaskPushNotificationConfig
     ) -> a2a_pb2.TaskPushNotificationConfig:
         return a2a_pb2.TaskPushNotificationConfig(
-            name=f'tasks/{config.task_id}/pushNotificationConfigs/{config.task_id}',
+            name=f'tasks/{config.task_id}/pushNotificationConfigs/{config.push_notification_config.id}',
             push_notification_config=cls.push_notification_config(
                 config.push_notification_config,
             ),