### 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)
settings_menu->add_shortcut(ED_GET_SHORTCUT("editor/editor_settings"), SETTINGS_PREFERENCES);
	settings_menu->add_shortcut(ED_SHORTCUT("editor/command_palette", TTR("Command Palette..."), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::P), HELP_COMMAND_PALETTE);
	settings_menu->add_separator();
	editor_layouts = memnew(PopupMenu);
	editor_layouts->set_name("Layouts");
	editor_layouts->set_auto_translate(false);
	settings_menu->add_child(editor_layouts);
	editor_layouts->connect("id_pressed", callable_mp(this, &EditorNode::_layout_menu_option));
	settings_menu->add_submenu_item(TTR("Editor Layout"), "Layouts");
	settings_menu->add_separator();
	ED_SHORTCUT_AND_COMMAND("editor/take_screenshot", TTR("Take Screenshot"), KeyModifierMask::CTRL | Key::F12);
	ED_SHORTCUT_OVERRIDE("editor/take_screenshot", "macos", KeyModifierMask::META | Key::F12);
	settings_menu->add_shortcut(ED_GET_SHORTCUT("editor/take_screenshot"), EDITOR_SCREENSHOT);
	settings_menu->set_item_tooltip(-1, TTR("Screenshots are stored in the Editor Data/Settings Folder."));
#ifndef ANDROID_ENABLED
	ED_SHORTCUT_AND_COMMAND("editor/fullscreen_mode", TTR("Toggle Fullscreen"), KeyModifierMask::SHIFT | Key::F11);
	ED_SHORTCUT_OVERRIDE("editor/fullscreen_mode", "macos", KeyModifierMask::META | KeyModifierMask::CTRL | Key::F);
	settings_menu->add_shortcut(ED_GET_SHORTCUT("editor/fullscreen_mode"), SETTINGS_TOGGLE_FULLSCREEN);
#endif
	settings_menu->add_separator();
#ifndef ANDROID_ENABLED
	if (OS::get_singleton()->get_data_path() == OS::get_singleton()->get_config_path()) {
		
		settings_menu->add_item(TTR("Open Editor Data/Settings Folder"), SETTINGS_EDITOR_DATA_FOLDER);
	} else {
		
		settings_menu->add_item(TTR("Open Editor Data Folder"), SETTINGS_EDITOR_DATA_FOLDER);
		settings_menu->add_item(TTR("Open Editor Settings Folder"), SETTINGS_EDITOR_CONFIG_FOLDER);
	}
	settings_menu->add_separator();