### 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 *edited_scene_root = editor_data.get_edited_scene_root(i);
			if (edited_scene_root) {
				List<Node *> valid_nodes;
				find_all_instances_inheriting_path_in_node(edited_scene_root, edited_scene_root, p_instance_path, valid_nodes);
				if (valid_nodes.size() > 0) {
					edited_scene_map[i] = valid_nodes;
				}
			}
		}
	}
	if (edited_scene_map.size() > 0) {
		
		Error err;
		Ref<PackedScene> instance_scene_packed_scene = ResourceLoader::load(p_instance_path, "", ResourceFormatLoader::CACHE_MODE_IGNORE, &err);
		instance_scene_packed_scene->set_path(p_instance_path, true);
		ERR_FAIL_COND(err != OK);
		ERR_FAIL_COND(instance_scene_packed_scene.is_null());
		HashMap<String, Ref<PackedScene>> local_scene_cache;
		local_scene_cache[p_instance_path] = instance_scene_packed_scene;
		for (const KeyValue<int, List<Node *>> &edited_scene_map_elem : edited_scene_map) {
			
			int current_scene_idx = edited_scene_map_elem.key;
			editor_data.set_edited_scene(current_scene_idx);
			Node *current_edited_scene = editor_data.get_edited_scene_root(current_scene_idx);
			
			EditorUndoRedoManager::get_singleton()->clear_history();
			
			editor_data.is_scene_changed(current_scene_idx);
			for (Node *original_node : edited_scene_map_elem.value) {