### 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)
err = docs.save_classes(doc_tool_path, doc_data_classes, false);
			ERR_FAIL_COND_V_MSG(err != OK, false, "Error saving GDScript docs:" + itos(err));
			OS::get_singleton()->set_exit_code(EXIT_SUCCESS);
			return false;
		}
#endif 
		EditorNode *editor_node = nullptr;
		if (editor) {
			OS::get_singleton()->benchmark_begin_measure("editor");
			editor_node = memnew(EditorNode);
			sml->get_root()->add_child(editor_node);
			if (!_export_preset.is_empty()) {
				editor_node->export_preset(_export_preset, positional_arg, export_debug, export_pack_only);
				game_path = ""; /
			}
			OS::get_singleton()->benchmark_end_measure("editor");
		}
#endif
		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"));
		if (!editor && !project_manager) {
			/
			String stretch_mode = GLOBAL_GET("display/window/stretch/mode");
			String stretch_aspect = GLOBAL_GET("display/window/stretch/aspect");
			Size2i stretch_size = Size2i(GLOBAL_GET("display/window/size/viewport_width"),
					GLOBAL_GET("display/window/size/viewport_height"));
			real_t stretch_scale = GLOBAL_GET("display/window/stretch/scale");
			String stretch_scale_mode = GLOBAL_GET("display/window/stretch/scale_mode");
			Window::ContentScaleMode cs_sm = Window::CONTENT_SCALE_MODE_DISABLED;
			if (stretch_mode == "canvas_items") {