### 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)
RenderingServer::get_singleton()->is_render_loop_enabled()) {
		if ((!force_redraw_requested) && OS::get_singleton()->is_in_low_processor_usage_mode()) {
			if (RenderingServer::get_singleton()->has_changed()) {
				RenderingServer::get_singleton()->draw(true, scaled_step); /
				Engine::get_singleton()->frames_drawn++;
			}
		} else {
			RenderingServer::get_singleton()->draw(true, scaled_step); /
			Engine::get_singleton()->frames_drawn++;
			force_redraw_requested = false;
		}
	}
	process_ticks = OS::get_singleton()->get_ticks_usec() - process_begin;
	process_max = MAX(process_ticks, process_max);
	uint64_t frame_time = OS::get_singleton()->get_ticks_usec() - ticks;
	for (int i = 0; i < ScriptServer::get_language_count(); i++) {
		ScriptServer::get_language(i)->frame();
	}
	AudioServer::get_singleton()->update();
	if (EngineDebugger::is_active()) {
		EngineDebugger::get_singleton()->iteration(frame_time, process_ticks, physics_process_ticks, physics_step);
	}
	frames++;
	Engine::get_singleton()->_process_frames++;
	if (frame > 1000000) {
		/
		if (hide_print_fps_attempts == 0) {
			if (editor || project_manager) {
				if (print_fps) {
					print_line(vformat("Editor FPS: %d (%s mspf)", frames, rtos(1000.0 / frames).pad_decimals(2)));