### 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)
load_task.type_hint = p_type_hint;
			load_task.cache_mode = p_cache_mode;
			load_task.use_sub_threads = p_thread_mode == LOAD_THREAD_DISTRIBUTE;
			if (p_cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
				Ref<Resource> existing = ResourceCache::get_ref(local_path);
				if (existing.is_valid()) {
					
					load_task.resource = existing;
					load_task.status = THREAD_LOAD_LOADED;
					load_task.progress = 1.0;
					thread_load_tasks[local_path] = load_task;
					return load_token;
				}
			}
			
			must_not_register = thread_load_tasks.has(local_path) && p_cache_mode == ResourceFormatLoader::CACHE_MODE_IGNORE;
			if (must_not_register) {
				load_token->local_path.clear();
				unregistered_load_task = load_task;
			} else {
				thread_load_tasks[local_path] = load_task;
			}
			load_task_ptr = must_not_register ? &unregistered_load_task : &thread_load_tasks[local_path];
		}
		run_on_current_thread = must_not_register || p_thread_mode == LOAD_THREAD_FROM_CURRENT;
		if (run_on_current_thread) {
			load_task_ptr->thread_id = Thread::get_caller_id();
		} else {
			load_task_ptr->task_id = WorkerThreadPool::get_singleton()->add_native_task(&ResourceLoader::_thread_load_function, load_task_ptr);
		}