Bug in the NetworkRequesttask method which handles the timeout events

[Gpetrak]

After the last changes of the milestone 2.0, we modified the instance of the _pending_replies to return a PendingReply object instead of a tuple.
However, the method that handles the timeout events has to be adapted accordigly:
https://github.com/GeoNode/QGISGeoNodePlugin/blob/main/src/qgis_geonode/tasks/network_task.py#L179

because in case of a timout event, the plugin raises the following error:

{
  "ExceptionDetails": {
    "Type": "TypeError",
    "Message": "cannot unpack non-iterable PendingReply object"
  },
  "Environment": {
    "Qgis Version": "3.38.3-Grenoble",
    "Operating System": "linux",
    "Locale": "en"
  },
  "Trace": [
    {
      "Name": "_handle_request_timed_out",
      "Filename": "network_task.py",
      "LineNo": 179,
      "Variables": {
        "self": "<qgis_geonode.tasks.network_task.NetworkRequestTask object at 0x740d6d3f51b0>",
        "request_params": "<qgis._core.QgsNetworkRequestParameters object at 0x740d6d3f5360>"
      }
    }
  ]
}```