Custom class "Editor" can't be added to scene using "Create New Node" dialog.

### Tested versions

- Reproducible in: 3.4.4-stable, 3.5.3-stable, v4.2.1-stable, 4.3-dev3...

### System information

Godot v4.2.1.stable - Debian GNU/Linux 11 (bullseye) 11 - X11 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 Ti () - 11th Gen Intel(R) Core(TM) i5-11600K @ 3.90GHz (12 Threads)

### Issue description

Custom class "Editor" can't be created using "Create New Node" dialog.
Can be created in GDScript. Autocomplete works.


P.S. The same on Windows.

### Steps to reproduce

1. Create custom class "Editor" using "class_name Editor extends Control".
2. Save.
3. Add new scene.
4. Try to add node "Editor" using "Create New Node" dialog.

### Minimal reproduction project (MRP)

N/A

Reproduce the issue in Godot by defining `class_name Editor extends Control`, saving it, and trying to add it through the Create New Node dialog. Compare this with creating the class in GDScript and verify that the custom Editor class appears and can be instantiated from the dialog.

Written by the indexing model from the issue text.