### 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)
for (int i = 0; i < p_node->get_child_count(); i++) {
			Node *child = p_node->get_child(i);
			update_ownership_table_for_addition_node_ancestors(child, ownership_table);
		}
		new_additive_node_entry.ownership_table = ownership_table;
		p_addition_list.push_back(new_additive_node_entry);
		return;
	}
	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *child = p_node->get_child(i);
		update_diff_data_for_node(p_edited_scene, p_root, child, p_modification_table, p_addition_list);
	}
}
void EditorNode::open_request(const String &p_path) {
	if (!opening_prev) {
		List<String>::Element *prev_scene_item = previous_scenes.find(p_path);
		if (prev_scene_item != nullptr) {
			prev_scene_item->erase();
		}
	}
	load_scene(p_path); 
}
bool EditorNode::has_previous_scenes() const {
	return !previous_scenes.is_empty();
}
void EditorNode::edit_foreign_resource(Ref<Resource> p_resource) {
	load_scene(p_resource->get_path().get_slice("::", 0));
	InspectorDock::get_singleton()->call_deferred("edit_resource", p_resource);
}
bool EditorNode::is_resource_read_only(Ref<Resource> p_resource, bool p_foreign_resources_are_writable) {