### 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)
add_autoload->set_text(TTR("Add"));
	add_autoload->connect("pressed", callable_mp(this, &EditorAutoloadSettings::_autoload_add));
	
	add_autoload->set_disabled(true);
	hbc->add_child(add_autoload);
	tree = memnew(Tree);
	tree->set_hide_root(true);
	tree->set_select_mode(Tree::SELECT_MULTI);
	tree->set_allow_reselect(true);
	SET_DRAG_FORWARDING_GCD(tree, EditorAutoloadSettings);
	tree->set_columns(4);
	tree->set_column_titles_visible(true);
	tree->set_column_title(0, TTR("Name"));
	tree->set_column_expand(0, true);
	tree->set_column_expand_ratio(0, 1);
	tree->set_column_title(1, TTR("Path"));
	tree->set_column_expand(1, true);
	tree->set_column_clip_content(1, true);
	tree->set_column_expand_ratio(1, 2);
	tree->set_column_title(2, TTR("Global Variable"));
	tree->set_column_expand(2, false);
	tree->set_column_expand(3, false);
	tree->connect("cell_selected", callable_mp(this, &EditorAutoloadSettings::_autoload_selected));
	tree->connect("item_edited", callable_mp(this, &EditorAutoloadSettings::_autoload_edited));
	tree->connect("button_clicked", callable_mp(this, &EditorAutoloadSettings::_autoload_button_pressed));
	tree->connect("item_activated", callable_mp(this, &EditorAutoloadSettings::_autoload_activated));
	tree->set_v_size_flags(SIZE_EXPAND_FILL);
	add_child(tree, true);
}
EditorAutoloadSettings::~EditorAutoloadSettings() {