### 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)
update_spinner_step_frame = frame + 1;
				
				if (EDITOR_GET("interface/editor/show_update_spinner")) {
					update_spinner->set_icon(theme->get_icon("Progress" + itos(update_spinner_step + 1), EditorStringName(EditorIcons)));
				}
			}
			editor_selection->update();
			ResourceImporterTexture::get_singleton()->update_imports();
			bottom_panel_updating = false;
			if (requested_first_scan) {
				requested_first_scan = false;
				OS::get_singleton()->benchmark_begin_measure("editor_scan_and_import");
				if (run_surface_upgrade_tool) {
					run_surface_upgrade_tool = false;
					SurfaceUpgradeTool::get_singleton()->connect("upgrade_finished", callable_mp(EditorFileSystem::get_singleton(), &EditorFileSystem::scan), CONNECT_ONE_SHOT);
					SurfaceUpgradeTool::get_singleton()->finish_upgrade();
				} else {
					EditorFileSystem::get_singleton()->scan();
				}
			}
		} break;
		case NOTIFICATION_ENTER_TREE: {
			get_tree()->set_disable_node_threading(true); 
			Engine::get_singleton()->set_editor_hint(true);
			Window *window = get_window();
			if (window) {
				
				window->connect("titlebar_changed", callable_mp(this, &EditorNode::_titlebar_resized));
			}