### 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)
} break;
		case EditorSettings::NOTIFICATION_EDITOR_SETTINGS_CHANGED: {
			FileDialog::set_default_show_hidden_files(EDITOR_GET("filesystem/file_dialog/show_hidden_files"));
			EditorFileDialog::set_default_show_hidden_files(EDITOR_GET("filesystem/file_dialog/show_hidden_files"));
			EditorFileDialog::set_default_display_mode((EditorFileDialog::DisplayMode)EDITOR_GET("filesystem/file_dialog/display_mode").operator int());
			bool theme_changed =
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/theme") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/editor/font") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/editor/main_font") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/editor/code_font") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("text_editor/theme") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("text_editor/help/help") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("filesystem/file_dialog/thumbnail_size") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("run/output/font_size") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/touchscreen/increase_scrollbar_touch_area") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/touchscreen/scale_gizmo_handles");
			if (theme_changed) {
				_update_theme();
			}
			scene_tabs->update_scene_tabs();
			recent_scenes->reset_size();
			_build_icon_type_cache();
			HashSet<String> updated_textfile_extensions;
			bool extensions_match = true;
			const Vector<String> textfile_ext = ((String)(EDITOR_GET("docks/filesystem/textfile_extensions"))).split(",", false);
			for (const String &E : textfile_ext) {
				updated_textfile_extensions.insert(E);
				if (extensions_match && !textfile_extensions.has(E)) {
					extensions_match = false;
				}