### 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)
current_renderer = current_renderer.to_lower();
	for (int i = 0; i < renderers.size(); i++) {
		String rendering_method = renderers[i];
		
		if (rendering_method == "forward_plus") {
			renderer->add_item(TTR("Forward+"));
		}
		if (rendering_method == "mobile") {
			renderer->add_item(TTR("Mobile"));
		}
		if (rendering_method == "gl_compatibility") {
			renderer->add_item(TTR("Compatibility"));
		}
		renderer->set_item_metadata(i, rendering_method);
		
		rendering_method = rendering_method.to_lower();
		if (current_renderer == rendering_method) {
			renderer->select(i);
			renderer_current = i;
		}
	}
	_update_renderer_color();
	video_restart_dialog = memnew(ConfirmationDialog);
	video_restart_dialog->set_text(TTR("Changing the renderer requires restarting the editor."));
	video_restart_dialog->set_ok_button_text(TTR("Save & Restart"));
	video_restart_dialog->connect("confirmed", callable_mp(this, &EditorNode::_menu_option).bind(SET_RENDERER_NAME_SAVE_AND_RESTART));
	gui_base->add_child(video_restart_dialog);
	progress_hb = memnew(BackgroundProgress);