### 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 (!init_use_custom_screen) {
				init_screen = GLOBAL_GET("display/window/size/initial_screen").operator int();
				init_use_custom_screen = true;
			}
		} else if (initial_position_type == 3) { 
			if (!init_use_custom_screen) {
				init_screen = DisplayServer::SCREEN_WITH_MOUSE_FOCUS;
				init_use_custom_screen = true;
			}
		} else if (initial_position_type == 4) { 
			if (!init_use_custom_screen) {
				init_screen = DisplayServer::SCREEN_WITH_KEYBOARD_FOCUS;
				init_use_custom_screen = true;
			}
		}
	}
	GLOBAL_DEF("internationalization/locale/include_text_server_data", false);
	OS::get_singleton()->_allow_hidpi = GLOBAL_DEF("display/window/dpi/allow_hidpi", true);
	OS::get_singleton()->_allow_layered = GLOBAL_DEF("display/window/per_pixel_transparency/allowed", false);
#ifdef TOOLS_ENABLED
	if (editor || project_manager) {
		
		OS::get_singleton()->_allow_hidpi = true;
		
		OS::get_singleton()->set_environment("DISABLE_MANGOHUD", "1"); 
		OS::get_singleton()->set_environment("DISABLE_RTSS_LAYER", "1"); 
		OS::get_singleton()->set_environment("DISABLE_VKBASALT", "1");
	} else {
		
		OS::get_singleton()->unset_environment("DISABLE_MANGOHUD");