### 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)
undo_redo->create_action(TTR("Add Autoload"));
	
	undo_redo->add_do_property(ProjectSettings::get_singleton(), name, "*" + p_path);
	if (ProjectSettings::get_singleton()->has_setting(name)) {
		undo_redo->add_undo_property(ProjectSettings::get_singleton(), name, GLOBAL_GET(name));
	} else {
		undo_redo->add_undo_property(ProjectSettings::get_singleton(), name, Variant());
	}
	undo_redo->add_do_method(this, "update_autoload");
	undo_redo->add_undo_method(this, "update_autoload");
	undo_redo->add_do_method(this, "emit_signal", autoload_changed);
	undo_redo->add_undo_method(this, "emit_signal", autoload_changed);
	undo_redo->commit_action();
	return true;
}
void EditorAutoloadSettings::autoload_remove(const String &p_name) {
	String name = "autoload/" + p_name;
	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
	int order = ProjectSettings::get_singleton()->get_order(name);
	undo_redo->create_action(TTR("Remove Autoload"));
	undo_redo->add_do_property(ProjectSettings::get_singleton(), name, Variant());
	undo_redo->add_undo_property(ProjectSettings::get_singleton(), name, GLOBAL_GET(name));
	undo_redo->add_undo_method(ProjectSettings::get_singleton(), "set_order", name, order);
	undo_redo->add_do_method(this, "update_autoload");
	undo_redo->add_undo_method(this, "update_autoload");
	undo_redo->add_do_method(this, "emit_signal", autoload_changed);
	undo_redo->add_undo_method(this, "emit_signal", autoload_changed);
	undo_redo->commit_action();
}
void EditorAutoloadSettings::_bind_methods() {