Connecting callable in tool script with persist flag and bound object will serialize bound object

### Tested versions

- Reproducible in: v4.4.1.stable.mono.arch_linux

### System information

Godot v4.4.1.stable.mono unknown - EndeavourOS #1 SMP PREEMPT_DYNAMIC Tue, 29 Apr 2025 09:23:13 +0000 on X11 - X11 display driver, Multi-window, 2 monitors - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1650 (nvidia; 570.144) - Intel(R) Core(TM) i5-9300H CPU @ 2.40GHz (8 threads)

### Issue description

When instantiating scene it will recreate bound object as a completely new one. Now it will not only pass the wrong object, it will also leak memory, both in editor and in game.

After thinking about it, I get why it doesn't work, but a warning would be nice. Maybe don't serialize it at all if it detects bound object and push an error instead

### Steps to reproduce

Bind an object to callable and connect it to signal with CONNECT_PERSIST flag in tool script, object could be a node

### Minimal reproduction project (MRP)

You can open `.tscn` file and see that it serialized bound `Node`
[wrong_callable.zip](https://github.com/user-attachments/files/20529588/wrong_callable.zip)