### 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)
DisplayServer::get_singleton()->cursor_set_custom_image(Ref<Resource>());
	}
	SceneState::set_disable_placeholders(true);
	ResourceLoader::clear_translation_remaps(); 
	ResourceLoader::clear_path_remaps();
	ResourceLoader::set_create_missing_resources_if_class_unavailable(true);
	EditorPropertyNameProcessor *epnp = memnew(EditorPropertyNameProcessor);
	add_child(epnp);
	EditorUndoRedoManager::get_singleton()->connect("version_changed", callable_mp(this, &EditorNode::_update_undo_redo_allowed));
	EditorUndoRedoManager::get_singleton()->connect("history_changed", callable_mp(this, &EditorNode::_update_undo_redo_allowed));
	ProjectSettings::get_singleton()->connect("settings_changed", callable_mp(this, &EditorNode::_update_from_settings));
	GDExtensionManager::get_singleton()->connect("extensions_reloaded", callable_mp(this, &EditorNode::_gdextensions_reloaded));
	TranslationServer::get_singleton()->set_enabled(false);
	
	if (!EditorSettings::get_singleton()) {
		EditorSettings::create();
	}
	FileAccess::set_backup_save(EDITOR_GET("filesystem/on_save/safe_save_on_backup_then_rename"));
	
	surface_upgrade_tool = memnew(SurfaceUpgradeTool);
	run_surface_upgrade_tool = EditorSettings::get_singleton()->get_project_metadata("surface_upgrade_tool", "run_on_restart", false);
	if (run_surface_upgrade_tool) {
		SurfaceUpgradeTool::get_singleton()->begin_upgrade();
	}
	{
		int display_scale = EDITOR_GET("interface/editor/display_scale");
		switch (display_scale) {
			case 0:
				
				EditorScale::set_scale(EditorSettings::get_singleton()->get_auto_display_scale());