### 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)
goto_menu = memnew(MenuButton);
	goto_menu->set_text(TTR("Go To"));
	goto_menu->set_switch_on_hover(true);
	goto_menu->set_shortcut_context(this);
	bookmarks_menu = memnew(PopupMenu);
	bookmarks_menu->set_name("BookmarksMenu");
	breakpoints_menu = memnew(PopupMenu);
	breakpoints_menu->set_name("BreakpointsMenu");
	connection_info_dialog = memnew(ConnectionInfoDialog);
	SET_DRAG_FORWARDING_GCD(code_editor->get_text_editor(), ScriptTextEditor);
}
ScriptTextEditor::~ScriptTextEditor() {
	highlighters.clear();
	if (!editor_enabled) {
		memdelete(code_editor);
		memdelete(warnings_panel);
		memdelete(errors_panel);
		memdelete(context_menu);
		memdelete(color_panel);
		memdelete(edit_hb);
		memdelete(edit_menu);
		memdelete(highlighter_menu);
		memdelete(search_menu);
		memdelete(goto_menu);
		memdelete(bookmarks_menu);
		memdelete(breakpoints_menu);
		memdelete(connection_info_dialog);
	}
}
static ScriptEditorBase *create_editor(const Ref<Resource> &p_resource) {