### 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)
context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/unindent"), EDIT_UNINDENT);
	context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/toggle_comment"), EDIT_TOGGLE_COMMENT);
	context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/toggle_bookmark"), BOOKMARK_TOGGLE);
	if (p_selection) {
		context_menu->add_separator();
		context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/convert_to_uppercase"), EDIT_TO_UPPERCASE);
		context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/convert_to_lowercase"), EDIT_TO_LOWERCASE);
		context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/evaluate_selection"), EDIT_EVALUATE);
		context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/create_code_region"), EDIT_CREATE_CODE_REGION);
	}
	if (p_foldable) {
		context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/toggle_fold_line"), EDIT_TOGGLE_FOLD_LINE);
	}
	if (p_color || p_open_docs || p_goto_definition) {
		context_menu->add_separator();
		if (p_open_docs) {
			context_menu->add_item(TTR("Lookup Symbol"), LOOKUP_SYMBOL);
		}
		if (p_color) {
			context_menu->add_item(TTR("Pick Color"), EDIT_PICK_COLOR);
		}
	}
	const CodeEdit *tx = code_editor->get_text_editor();
	context_menu->set_item_disabled(context_menu->get_item_index(EDIT_UNDO), !tx->has_undo());
	context_menu->set_item_disabled(context_menu->get_item_index(EDIT_REDO), !tx->has_redo());
	context_menu->set_position(get_screen_position() + p_pos);
	context_menu->reset_size();
	context_menu->popup();
}
void ScriptTextEditor::_enable_code_editor() {