### 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)
/
			Crypto::load_default_certificates(
					EditorSettings::get_singleton()->get_setting("network/tls/editor_tls_certificates").operator String());
		}
#endif
	}
	if (!has_icon && OS::get_singleton()->get_bundle_icon_path().is_empty()) {
		Ref<Image> icon = memnew(Image(app_icon_png));
		DisplayServer::get_singleton()->set_icon(icon);
	}
	if (movie_writer) {
		movie_writer->begin(DisplayServer::get_singleton()->window_get_size(), fixed_fps, Engine::get_singleton()->get_write_movie_path());
	}
	if (minimum_time_msec) {
		uint64_t minimum_time = 1000 * minimum_time_msec;
		uint64_t elapsed_time = OS::get_singleton()->get_ticks_usec();
		if (elapsed_time < minimum_time) {
			OS::get_singleton()->delay_usec(minimum_time - elapsed_time);
		}
	}
	OS::get_singleton()->benchmark_end_measure("startup_begin");
	OS::get_singleton()->benchmark_dump();
	return true;
}
/* Main iteration
 *
 * This is the iteration of the engine's game loop, advancing the state of physics,
 * rendering and audio.
 * It's called directly by the platform's OS::run method, where the loop is created
 * and monitored.