### 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)
Node *scene = editor_data.get_edited_scene_root(p_idx);
	if (!scene) {
		return;
	}
	String path = EditorPaths::get_singleton()->get_project_settings_dir().path_join(p_file.get_file() + "-editstate-" + p_file.md5_text() + ".cfg");
	Ref<ConfigFile> cf;
	cf.instantiate();
	Dictionary md;
	if (p_idx < 0 || editor_data.get_edited_scene() == p_idx) {
		md = editor_data.get_editor_plugin_states();
	} else {
		md = editor_data.get_scene_editor_states(p_idx);
	}
	List<Variant> keys;
	md.get_key_list(&keys);
	for (const Variant &E : keys) {
		cf->set_value("editor_states", E, md[E]);
	}
	
	List<Node *> selection = editor_selection->get_full_selected_node_list();
	TypedArray<NodePath> selection_paths;
	for (Node *selected_node : selection) {
		selection_paths.push_back(selected_node->get_path());
	}
	cf->set_value("editor_states", "selected_nodes", selection_paths);
	Error err = cf->save(path);
	ERR_FAIL_COND_MSG(err != OK, "Cannot save config file to '" + path + "'.");
}
bool EditorNode::_find_and_save_resource(Ref<Resource> p_res, HashMap<Ref<Resource>, bool> &processed, int32_t flags) {