### 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)
int selected_main_editor_idx = p_config_file->get_value(EDITOR_NODE_CONFIG_SECTION, "selected_main_editor_idx");
		if (selected_main_editor_idx >= 0 && selected_main_editor_idx < main_editor_buttons.size()) {
			callable_mp(this, &EditorNode::editor_select).call_deferred(selected_main_editor_idx);
		}
	}
}
void EditorNode::_load_open_scenes_from_config(Ref<ConfigFile> p_layout) {
	if (!bool(EDITOR_GET("interface/scene_tabs/restore_scenes_on_load"))) {
		return;
	}
	if (!p_layout->has_section(EDITOR_NODE_CONFIG_SECTION) ||
			!p_layout->has_section_key(EDITOR_NODE_CONFIG_SECTION, "open_scenes")) {
		return;
	}
	restoring_scenes = true;
	PackedStringArray scenes = p_layout->get_value(EDITOR_NODE_CONFIG_SECTION, "open_scenes");
	for (int i = 0; i < scenes.size(); i++) {
		load_scene(scenes[i]);
	}
	if (p_layout->has_section_key(EDITOR_NODE_CONFIG_SECTION, "current_scene")) {
		String current_scene = p_layout->get_value(EDITOR_NODE_CONFIG_SECTION, "current_scene");
		int current_scene_idx = scenes.find(current_scene);
		if (current_scene_idx >= 0) {
			_set_current_scene(current_scene_idx);
		}
	}
	save_editor_layout_delayed();
	restoring_scenes = false;
}
bool EditorNode::has_scenes_in_session() {