### 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)
}
		if (!text_driver_options.is_empty() && text_driver_options.find(",") == -1) {
			/
			text_driver_options += ",";
		}
		text_driver_options += driver_name;
	}
	ProjectSettings::get_singleton()->set_custom_property_info(PropertyInfo(Variant::STRING, "internationalization/rendering/text_driver", PROPERTY_HINT_ENUM, text_driver_options));
	/
	if (text_driver.is_empty()) {
		text_driver = GLOBAL_GET("internationalization/rendering/text_driver");
	}
	if (!text_driver.is_empty()) {
		/
		for (int i = 0; i < TextServerManager::get_singleton()->get_interface_count(); i++) {
			if (TextServerManager::get_singleton()->get_interface(i)->get_name() == text_driver) {
				text_driver_idx = i;
				break;
			}
		}
	}
	if (text_driver_idx < 0) {
		/
		int max_features = 0;
		for (int i = 0; i < TextServerManager::get_singleton()->get_interface_count(); i++) {
			uint32_t features = TextServerManager::get_singleton()->get_interface(i)->get_features();
			int feature_number = 0;
			while (features) {
				feature_number += features & 1;
				features >>= 1;