### 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)
Ref<DirAccess> dir = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
	ERR_FAIL_COND(dir.is_null());
	for (int i = 0; i < p_files.size(); i++) {
		String from = p_files[i];
		String to = to_path.path_join(from.get_file());
		if (dir->dir_exists(from)) {
			Vector<String> sub_files;
			Ref<DirAccess> sub_dir = DirAccess::open(from);
			ERR_FAIL_COND(sub_dir.is_null());
			sub_dir->list_dir_begin();
			String next_file = sub_dir->get_next();
			while (!next_file.is_empty()) {
				if (next_file == "." || next_file == "..") {
					next_file = sub_dir->get_next();
					continue;
				}
				sub_files.push_back(from.path_join(next_file));
				next_file = sub_dir->get_next();
			}
			if (!sub_files.is_empty()) {
				dir->make_dir(to);
				_add_dropped_files_recursive(sub_files, to);
			}
			continue;
		}
		dir->copy(from, to);
	}
}
void EditorNode::_file_access_close_error_notify(const String &p_str) {