`MultiMeshInstance3D` throws errors in editor when its scene is opened and a parent scene is also open

### Tested versions

Reproducible in 4.4.1.stable, 4.5.dev3.

### System information

Godot v4.5.dev3 - Windows 11 (build 26100) - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1660 SUPER (NVIDIA; 32.0.15.6636) - Intel(R) Core(TM) i7-10700F CPU @ 2.90GHz (16 threads)

### Issue description

**IF**:
- There's a Scene A that contains instance(s) of Scene B, AND...
- Scene B contains a `MultiMeshInstance3D`, AND...
- Scene A is already open

**THEN**:
- Whenever Scene B is opened or reloaded, the `MultiMeshInstance3D` will throw errors about its properties that are set to non-default values and are listed before the `Instance Count` property and are dependent on it to be zero.

Example errors:
```
ERROR: Instance count must be 0 to change the transform format.
ERROR: Instance count must be 0 to toggle whether colors are used.
ERROR: Instance count must be 0 to toggle whether custom data is used.
```

### Steps to reproduce

- Open the attached project and open up `test.tscn`. This will be "Scene A".
- Open up `donuts.tscn`. This is "Scene B".
- Observe the errors in the console.
- Reload `donuts.tscn`.
- Observe the errors in the console.

### Minimal reproduction project (MRP)

[bug-report.zip](https://github.com/user-attachments/files/20514286/bug-report.zip)