### 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)
reload_scene(E);
		reload_instances_with_path_in_edited_scenes(E);
	}
	scene_tabs->set_current_tab(current_tab);
}
void EditorNode::_sources_changed(bool p_exist) {
	if (waiting_for_first_scan) {
		waiting_for_first_scan = false;
		OS::get_singleton()->benchmark_end_measure("editor_scan_and_import");
		
		
		RenderingServer::get_singleton()->global_shader_parameters_load_settings(true);
		_load_editor_layout();
		if (!defer_load_scene.is_empty()) {
			OS::get_singleton()->benchmark_begin_measure("editor_load_scene");
			load_scene(defer_load_scene);
			defer_load_scene = "";
			OS::get_singleton()->benchmark_end_measure("editor_load_scene");
			OS::get_singleton()->benchmark_dump();
		}
		if (SurfaceUpgradeTool::get_singleton()->is_show_requested()) {
			SurfaceUpgradeTool::get_singleton()->show_popup();
		}
		
		if (!singleton->cmdline_export_mode) {
			EditorResourcePreview::get_singleton()->start();
		}
	}
}
void EditorNode::_scan_external_changes() {