### 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)
} break;
		case SETTINGS_INSTALL_ANDROID_BUILD_TEMPLATE: {
			gradle_build_manage_templates->hide();
			file_android_build_source->popup_centered_ratio();
		} break;
		case SETTINGS_MANAGE_FEATURE_PROFILES: {
			feature_profile_manager->popup_centered_clamped(Size2(900, 800) * EDSCALE, 0.8);
		} break;
		case SETTINGS_TOGGLE_FULLSCREEN: {
			DisplayServer::WindowMode mode = DisplayServer::get_singleton()->window_get_mode();
			if (mode == DisplayServer::WINDOW_MODE_FULLSCREEN || mode == DisplayServer::WINDOW_MODE_EXCLUSIVE_FULLSCREEN) {
				DisplayServer::get_singleton()->window_set_mode(prev_mode);
			} else {
				prev_mode = mode;
				DisplayServer::get_singleton()->window_set_mode(DisplayServer::WINDOW_MODE_FULLSCREEN);
			}
		} break;
		case EDITOR_SCREENSHOT: {
			screenshot_timer->start();
		} break;
		case SETTINGS_PICK_MAIN_SCENE: {
			file->set_file_mode(EditorFileDialog::FILE_MODE_OPEN_FILE);
			List<String> extensions;
			ResourceLoader::get_recognized_extensions_for_type("PackedScene", &extensions);
			file->clear_filters();
			for (int i = 0; i < extensions.size(); i++) {
				file->add_filter("*." + extensions[i], extensions[i].to_upper());
			}
			Node *scene = editor_data.get_edited_scene_root();
			if (scene) {