"Remove checking of PONG event after receiving data"

As websockets sansio protocol is not propagating this event after receiving data

uvicorn/protocols/websockets/websockets_sansio_impl.py

@@ -138,8 +138,6 @@ def handle_events(self) -> None:
                     self.handle_bytes(event)
                 elif event.opcode == Opcode.PING:
                     self.handle_ping(event)
-                elif event.opcode == Opcode.PONG:
-                    self.handle_pong(event)
                 elif event.opcode == Opcode.CLOSE:
                     self.handle_close(event)
 
@@ -217,9 +215,6 @@ def handle_ping(self, event: Frame) -> None:
         output = self.conn.data_to_send()
         self.transport.writelines(output)
 
-    def handle_pong(self, event: Frame) -> None:
-        pass
-
     def handle_close(self, event: Frame) -> None:
         if not self.close_sent and not self.transport.is_closing():
             disconnect_event: WebSocketDisconnectEvent = {