fix: pending streams not failed when GOAWAY is received (#50)

Author: quettabit

src/s2_sdk/_client.py

@@ -948,6 +948,8 @@ def _handle_event(self, event: h2.events.Event) -> None:
                 for stream_id, state in self._streams.items():
                     if stream_id > event.last_stream_id:
                         self._fail_stream(state, err)
+                for state in self._pending_streams.values():
+                    self._fail_stream(state, err)
             else:
                 self._fail_all_streams(err)