### 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)
install_android_build_template->popup_centered();
				} else {
					gradle_build_manage_templates->popup_centered();
				}
			}
		} break;
		case TOOLS_BUILD_PROFILE_MANAGER: {
			build_profile_manager->popup_centered_clamped(Size2(700, 800) * EDSCALE, 0.8);
		} break;
		case RUN_USER_DATA_FOLDER: {
			
			OS::get_singleton()->ensure_user_data_dir();
			OS::get_singleton()->shell_show_in_file_manager(OS::get_singleton()->get_user_data_dir(), true);
		} break;
		case FILE_EXPLORE_ANDROID_BUILD_TEMPLATES: {
			OS::get_singleton()->shell_show_in_file_manager(ProjectSettings::get_singleton()->get_resource_path().path_join("android"), true);
		} break;
		case FILE_QUIT:
		case RUN_PROJECT_MANAGER:
		case RELOAD_CURRENT_PROJECT: {
			if (p_confirmed && plugin_to_save) {
				plugin_to_save->save_external_data();
				p_confirmed = false;
			}
			if (!p_confirmed) {
				bool save_each = EDITOR_GET("interface/editor/save_each_scene_on_quit");
				if (_next_unsaved_scene(!save_each) == -1) {
					if (EditorUndoRedoManager::get_singleton()->is_history_unsaved(EditorUndoRedoManager::GLOBAL_HISTORY)) {
						if (p_option == RELOAD_CURRENT_PROJECT) {
							save_confirmation->set_ok_button_text(TTR("Save & Reload"));