### 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<ConfigFile> cf;
	cf.instantiate();
	if (!DirAccess::exists(addon_path.get_base_dir())) {
		_remove_plugin_from_enabled(addon_path);
		WARN_PRINT("Addon '" + addon_path + "' failed to load. No directory found. Removing from enabled plugins.");
		return;
	}
	Error err = cf->load(addon_path);
	if (err != OK) {
		show_warning(vformat(TTR("Unable to enable addon plugin at: '%s' parsing of config failed."), addon_path));
		return;
	}
	String plugin_version;
	if (cf->has_section_key("plugin", "version")) {
		plugin_version = cf->get_value("plugin", "version");
	}
	if (!cf->has_section_key("plugin", "script")) {
		show_warning(vformat(TTR("Unable to find script field for addon plugin at: '%s'."), addon_path));
		return;
	}
	String script_path = cf->get_value("plugin", "script");
	Ref<Script> scr; 
	
	if (script_path.length() > 0) {
		script_path = addon_path.get_base_dir().path_join(script_path);
		scr = ResourceLoader::load(script_path, "Script", ResourceFormatLoader::CACHE_MODE_IGNORE);
		if (scr.is_null()) {
			show_warning(vformat(TTR("Unable to load addon script from path: '%s'."), script_path));
			return;