### 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)
cs_sm = Window::CONTENT_SCALE_MODE_CANVAS_ITEMS;
			} else if (stretch_mode == "viewport") {
				cs_sm = Window::CONTENT_SCALE_MODE_VIEWPORT;
			}
			Window::ContentScaleAspect cs_aspect = Window::CONTENT_SCALE_ASPECT_IGNORE;
			if (stretch_aspect == "keep") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_KEEP;
			} else if (stretch_aspect == "keep_width") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_KEEP_WIDTH;
			} else if (stretch_aspect == "keep_height") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_KEEP_HEIGHT;
			} else if (stretch_aspect == "expand") {
				cs_aspect = Window::CONTENT_SCALE_ASPECT_EXPAND;
			}
			Window::ContentScaleStretch cs_stretch = Window::CONTENT_SCALE_STRETCH_FRACTIONAL;
			if (stretch_scale_mode == "integer") {
				cs_stretch = Window::CONTENT_SCALE_STRETCH_INTEGER;
			}
			sml->get_root()->set_content_scale_mode(cs_sm);
			sml->get_root()->set_content_scale_aspect(cs_aspect);
			sml->get_root()->set_content_scale_stretch(cs_stretch);
			sml->get_root()->set_content_scale_size(stretch_size);
			sml->get_root()->set_content_scale_factor(stretch_scale);
			sml->set_auto_accept_quit(GLOBAL_GET("application/config/auto_accept_quit"));
			sml->set_quit_on_go_back(GLOBAL_GET("application/config/quit_on_go_back"));
			String appname = GLOBAL_GET("application/config/name");
			appname = TranslationServer::get_singleton()->translate(appname);
#ifdef DEBUG_ENABLED
			/
			/