### 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)
version_btn = memnew(LinkButton);
	version_btn->set_text(VERSION_FULL_CONFIG);
	String hash = String(VERSION_HASH);
	if (hash.length() != 0) {
		hash = " " + vformat("[%s]", hash.left(9));
	}
	
	version_btn->set_meta(META_TEXT_TO_COPY, "v" VERSION_FULL_BUILD + hash);
	
	version_btn->set_self_modulate(Color(1, 1, 1, 0.65));
	version_btn->set_underline_mode(LinkButton::UNDERLINE_MODE_ON_HOVER);
	version_btn->set_tooltip_text(TTR("Click to copy."));
	version_btn->connect("pressed", callable_mp(this, &EditorNode::_version_button_pressed));
	version_info_vbc->add_child(version_btn);
	
	Control *h_spacer = memnew(Control);
	bottom_panel_hb->add_child(h_spacer);
	bottom_panel_raise = memnew(Button);
	bottom_panel_hb->add_child(bottom_panel_raise);
	bottom_panel_raise->hide();
	bottom_panel_raise->set_flat(true);
	bottom_panel_raise->set_toggle_mode(true);
	bottom_panel_raise->set_shortcut(ED_SHORTCUT_AND_COMMAND("editor/bottom_panel_expand", TTR("Expand Bottom Panel"), KeyModifierMask::SHIFT | Key::F12));
	bottom_panel_raise->connect("toggled", callable_mp(this, &EditorNode::_bottom_panel_raise_toggled));
	log = memnew(EditorLog);
	Button *output_button = add_bottom_panel_item(TTR("Output"), log);
	log->set_tool_button(output_button);
	center_split->connect("resized", callable_mp(this, &EditorNode::_vp_resized));
	native_shader_source_visualizer = memnew(EditorNativeShaderSourceVisualizer);
	gui_base->add_child(native_shader_source_visualizer);