### 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)
highlighter_menu->connect("id_pressed", callable_mp(this, &ScriptTextEditor::_change_syntax_highlighter));
	edit_hb->add_child(search_menu);
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/find"), SEARCH_FIND);
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/find_next"), SEARCH_FIND_NEXT);
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/find_previous"), SEARCH_FIND_PREV);
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/replace"), SEARCH_REPLACE);
	search_menu->get_popup()->add_separator();
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/find_in_files"), SEARCH_IN_FILES);
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/replace_in_files"), REPLACE_IN_FILES);
	search_menu->get_popup()->add_separator();
	search_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/contextual_help"), HELP_CONTEXTUAL);
	search_menu->get_popup()->connect("id_pressed", callable_mp(this, &ScriptTextEditor::_edit_option));
	_load_theme_settings();
	edit_hb->add_child(goto_menu);
	goto_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/goto_function"), SEARCH_LOCATE_FUNCTION);
	goto_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/goto_line"), SEARCH_GOTO_LINE);
	goto_menu->get_popup()->add_separator();
	goto_menu->get_popup()->add_child(bookmarks_menu);
	goto_menu->get_popup()->add_submenu_item(TTR("Bookmarks"), "BookmarksMenu");
	_update_bookmark_list();
	bookmarks_menu->connect("about_to_popup", callable_mp(this, &ScriptTextEditor::_update_bookmark_list));
	bookmarks_menu->connect("index_pressed", callable_mp(this, &ScriptTextEditor::_bookmark_item_pressed));
	goto_menu->get_popup()->add_child(breakpoints_menu);
	goto_menu->get_popup()->add_submenu_item(TTR("Breakpoints"), "BreakpointsMenu");
	_update_breakpoint_list();
	breakpoints_menu->connect("about_to_popup", callable_mp(this, &ScriptTextEditor::_update_breakpoint_list));
	breakpoints_menu->connect("index_pressed", callable_mp(this, &ScriptTextEditor::_breakpoint_item_pressed));
	goto_menu->get_popup()->connect("id_pressed", callable_mp(this, &ScriptTextEditor::_edit_option));
}
ScriptTextEditor::ScriptTextEditor() {