### 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)
}
			if (!extensions_match || updated_textfile_extensions.size() < textfile_extensions.size()) {
				textfile_extensions = updated_textfile_extensions;
				EditorFileSystem::get_singleton()->scan();
			}
			_update_update_spinner();
		} break;
	}
}
void EditorNode::_update_update_spinner() {
	update_spinner->set_visible(!RenderingServer::get_singleton()->canvas_item_get_debug_redraw() && EDITOR_GET("interface/editor/show_update_spinner"));
	const bool update_continuously = EDITOR_GET("interface/editor/update_continuously");
	PopupMenu *update_popup = update_spinner->get_popup();
	update_popup->set_item_checked(update_popup->get_item_index(SETTINGS_UPDATE_CONTINUOUSLY), update_continuously);
	update_popup->set_item_checked(update_popup->get_item_index(SETTINGS_UPDATE_WHEN_CHANGED), !update_continuously);
	if (update_continuously) {
		update_spinner->set_tooltip_text(TTR("Spins when the editor window redraws.\nUpdate Continuously is enabled, which can increase power usage. Click to disable it."));
		
		
		
		
		const bool dark_theme = EditorSettings::get_singleton()->is_dark_theme();
		update_spinner->set_self_modulate(theme->get_color(SNAME("error_color"), EditorStringName(Editor)) * (dark_theme ? Color(1.1, 1.1, 1.1) : Color(4.25, 4.25, 4.25)));
	} else {
		update_spinner->set_tooltip_text(TTR("Spins when the editor window redraws."));
		update_spinner->set_self_modulate(Color(1, 1, 1));
	}
	OS::get_singleton()->set_low_processor_usage_mode(!update_continuously);
}
void EditorNode::_on_plugin_ready(Object *p_script, const String &p_activate_name) {