### 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)
}
			} else if (print_fps || GLOBAL_GET("debug/settings/stdout/print_fps")) {
				print_line(vformat("Project FPS: %d (%s mspf)", frames, rtos(1000.0 / frames).pad_decimals(2)));
			}
		} else {
			hide_print_fps_attempts--;
		}
		Engine::get_singleton()->_fps = frames;
		performance->set_process_time(USEC_TO_SEC(process_max));
		performance->set_physics_process_time(USEC_TO_SEC(physics_process_max));
		performance->set_navigation_process_time(USEC_TO_SEC(navigation_process_max));
		process_max = 0;
		physics_process_max = 0;
		navigation_process_max = 0;
		frame %= 1000000;
		frames = 0;
	}
	iterating--;
	/
	if (Input::get_singleton()->is_using_input_buffering() && !agile_input_event_flushing) {
		Input::get_singleton()->flush_buffered_events();
	}
	if (movie_writer) {
		movie_writer->add_frame();
	}
	if ((quit_after > 0) && (Engine::get_singleton()->_process_frames >= quit_after)) {
		exit = true;
	}
	if (fixed_fps != -1) {
		return exit;