Changing multiplayer_peer stops already spawned nodes from replicating

[Faless]

Originally posted by @masterthdev in #80701 (comment)

Changing MultiplayerAPI.multiplayer_peer resets tracked nodes too. After restarting server using code below, MultiplayerSpawners stop replicating existing nodes.

multiplayer.multiplayer_peer.close()
var peer := ENetMultiplayerPeer.new()
peer.create_server(port)
multiplayer.multiplayer_peer  = peer

When a client joins after restarting server, host logs these errors for each old node:

E 0:00:22:0468   _make_spawn_packet: Condition "!nid" is true. Returning: ERR_UNCONFIGURED
  <C++ Source>   modules/multiplayer/scene_replication_interface.cpp:479 @ _make_spawn_packet()
E 0:00:22:0468   _send_raw: Condition "!p_buffer || p_size < 1" is true. Returning: ERR_INVALID_PARAMETER
  <C++ Source>   modules/multiplayer/scene_replication_interface.cpp:462 @ _send_raw()