### 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)
disk_changed_list->clear();
	TreeItem *r = disk_changed_list->create_item();
	disk_changed_list->set_hide_root(true);
	bool need_reload = false;
	
	for (int i = 0; i < editor_data.get_edited_scene_count(); i++) {
		Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
		if (editor_data.get_scene_path(i) == "" || !da->file_exists(editor_data.get_scene_path(i))) {
			continue;
		}
		uint64_t last_date = editor_data.get_scene_modified_time(i);
		uint64_t date = FileAccess::get_modified_time(editor_data.get_scene_path(i));
		if (date > last_date) {
			TreeItem *ti = disk_changed_list->create_item(r);
			ti->set_text(0, editor_data.get_scene_path(i).get_file());
			need_reload = true;
		}
	}
	String project_settings_path = ProjectSettings::get_singleton()->get_resource_path().path_join("project.godot");
	if (FileAccess::get_modified_time(project_settings_path) > ProjectSettings::get_singleton()->get_last_saved_time()) {
		TreeItem *ti = disk_changed_list->create_item(r);
		ti->set_text(0, "project.godot");
		need_reload = true;
	}
	if (need_reload) {
		disk_changed->call_deferred(SNAME("popup_centered_ratio"), 0.3);
	}
}
void EditorNode::_resave_scenes(String p_str) {