### Godot version

4.1.3

### System information

Linux

### Issue description

I'm trying to make an editor plugin on Rust:

```rust
#[derive(GodotClass)]
#[class(tool, editor_plugin, init, base=EditorPlugin)]
pub struct MyEditorPluginBase {}
```

But due to some limitations, I still have to use GDScript for some specific things.

So I tried to make a subclass of this Rust class:

```gdscript
@tool
class_name MyEditorPlugin
extends MyEditorPluginBase
```

This would work if `MyEditorPluginBase` was a GDScript class, but since it's a GDExtension class in my case, it doesn't work:

> Unable to load addon script from path: 'res://addons/my_addon/my_editor_plugin.gd' Base type is not EditorPlugin.

But it obviously **IS** EditorPlugin!

![godot-editorplugin-docs](https://github.com/godotengine/godot/assets/3236464/4665deeb-30f0-45cd-bfff-56101b9d4875)

![godot-editorplugin](https://github.com/godotengine/godot/assets/3236464/b1b6ecb4-de22-4abd-91a3-e180691f67ee)

If I understand correctly, this behavior is caused by this function, which checks some mysterious "instance base type" instead of real inheritance:

https://github.com/godotengine/godot/blob/fa4a65387ea41506ecc519fc61a06da110dce51c/editor/editor_node.cpp#L3456-L3458

https://github.com/godotengine/godot/blob/fa4a65387ea41506ecc519fc61a06da110dce51c/modules/gdscript/gdscript.cpp#L260-L263

Since the [documentation](https://docs.godotengine.org/en/stable/tutorials/plugins/editor/making_plugins.html#the-script-file) doesn't say that the script must be a **direct** subclass of EditorPlugin (and an indirect subclass works fine in GDScript), I interpret this behavior as a Godot bug.

### Steps to reproduce

See above

### Minimal reproduction project

[gdext_editor_plugin_test.zip](https://github.com/godotengine/godot/files/13451014/gdext_editor_plugin_test.zip)
editor_data.set_edited_scene(p_idx);
	Node *new_scene = editor_data.get_edited_scene_root();
	if (Popup *p = Object::cast_to<Popup>(new_scene)) {
		p->show();
	}
	SceneTreeDock::get_singleton()->set_edited_scene(new_scene);
	if (get_tree()) {
		get_tree()->set_edited_scene_root(new_scene);
	}
	if (new_scene) {
		if (new_scene->get_parent() != scene_root) {
			scene_root->add_child(new_scene, true);
		}
	}
	Dictionary state = editor_data.restore_edited_scene_state(editor_selection, &editor_history);
	_edit_current(true);
	_update_title();
	scene_tabs->update_scene_tabs();
	if (tabs_to_close.is_empty()) {
		call_deferred(SNAME("_set_main_scene_state"), state, get_edited_scene()); 
	}
}
void EditorNode::setup_color_picker(ColorPicker *p_picker) {
	p_picker->set_editor_settings(EditorSettings::get_singleton());
	int default_color_mode = EDITOR_GET("interface/inspector/default_color_picker_mode");
	int picker_shape = EDITOR_GET("interface/inspector/default_color_picker_shape");
	p_picker->set_color_mode((ColorPicker::ColorModeType)default_color_mode);
	p_picker->set_picker_shape((ColorPicker::PickerShapeType)picker_shape);
}
bool EditorNode::is_scene_open(const String &p_path) {