### 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)
EditorNode::ExecuteThreadArgs *eta = (EditorNode::ExecuteThreadArgs *)p_ud;
	Error err = OS::get_singleton()->execute(eta->path, eta->args, &eta->output, &eta->exitcode, true, &eta->execute_output_mutex);
	print_verbose("Thread exit status: " + itos(eta->exitcode));
	if (err != OK) {
		eta->exitcode = err;
	}
	eta->done.set();
}
int EditorNode::execute_and_show_output(const String &p_title, const String &p_path, const List<String> &p_arguments, bool p_close_on_ok, bool p_close_on_errors, String *r_output) {
	if (execute_output_dialog) {
		execute_output_dialog->set_title(p_title);
		execute_output_dialog->get_ok_button()->set_disabled(true);
		execute_outputs->clear();
		execute_outputs->set_scroll_follow(true);
		EditorInterface::get_singleton()->popup_dialog_centered_ratio(execute_output_dialog);
	}
	ExecuteThreadArgs eta;
	eta.path = p_path;
	eta.args = p_arguments;
	eta.exitcode = 255;
	int prev_len = 0;
	eta.execute_output_thread.start(_execute_thread, &eta);