### 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)
Node *p_edited_scene,
		Node *p_root,
		Node *p_node,
		HashMap<NodePath, ModificationNodeEntry> &p_modification_table,
		List<AdditiveNodeEntry> &p_addition_list) {
	bool node_part_of_subscene = p_node != p_edited_scene &&
			p_edited_scene->get_scene_inherited_state().is_valid() &&
			p_edited_scene->get_scene_inherited_state()->find_node_by_path(p_edited_scene->get_path_to(p_node)) >= 0;
	
	Node *valid_node_owner = p_node->get_owner();
	while (valid_node_owner) {
		if (valid_node_owner == p_root) {
			break;
		}
		valid_node_owner = valid_node_owner->get_owner();
	}
	if ((valid_node_owner == p_root && (p_root != p_edited_scene || !p_edited_scene->get_scene_file_path().is_empty())) || node_part_of_subscene || p_node == p_root) {
		HashMap<StringName, Variant> modified_properties = get_modified_properties_for_node(p_node);
		
		List<Connection> connections_to;
		p_node->get_all_signal_connections(&connections_to);
		List<ConnectionWithNodePath> valid_connections_to;
		for (const Connection &c : connections_to) {
			Node *connection_target_node = Object::cast_to<Node>(c.callable.get_object());