### 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)
orphan_resources = memnew(OrphanResourcesDialog);
	gui_base->add_child(orphan_resources);
	surface_upgrade_dialog = memnew(SurfaceUpgradeDialog);
	gui_base->add_child(surface_upgrade_dialog);
	confirmation = memnew(ConfirmationDialog);
	gui_base->add_child(confirmation);
	confirmation->connect("confirmed", callable_mp(this, &EditorNode::_menu_confirm_current));
	save_confirmation = memnew(ConfirmationDialog);
	save_confirmation->add_button(TTR("Don't Save"), DisplayServer::get_singleton()->get_swap_cancel_ok(), "discard");
	gui_base->add_child(save_confirmation);
	save_confirmation->set_min_size(Vector2(450.0 * EDSCALE, 0));
	save_confirmation->connect("confirmed", callable_mp(this, &EditorNode::_menu_confirm_current));
	save_confirmation->connect("custom_action", callable_mp(this, &EditorNode::_discard_changes));
	gradle_build_manage_templates = memnew(ConfirmationDialog);
	gradle_build_manage_templates->set_text(TTR("Android build template is missing, please install relevant templates."));
	gradle_build_manage_templates->set_ok_button_text(TTR("Manage Templates"));
	gradle_build_manage_templates->add_button(TTR("Install from file"))->connect("pressed", callable_mp(this, &EditorNode::_menu_option).bind(SETTINGS_INSTALL_ANDROID_BUILD_TEMPLATE));
	gradle_build_manage_templates->connect("confirmed", callable_mp(this, &EditorNode::_menu_option).bind(SETTINGS_MANAGE_EXPORT_TEMPLATES));
	gui_base->add_child(gradle_build_manage_templates);
	file_android_build_source = memnew(EditorFileDialog);
	file_android_build_source->set_title(TTR("Select Android sources file"));
	file_android_build_source->set_access(EditorFileDialog::ACCESS_FILESYSTEM);
	file_android_build_source->set_file_mode(EditorFileDialog::FILE_MODE_OPEN_FILE);
	file_android_build_source->add_filter("*.zip");
	file_android_build_source->connect("file_selected", callable_mp(this, &EditorNode::_android_build_source_selected));
	gui_base->add_child(file_android_build_source);
	install_android_build_template = memnew(ConfirmationDialog);
	install_android_build_template->set_text(TTR("This will set up your project for gradle Android builds by installing the source template to \"res:android/build\".\nYou can then apply modifications and build your own custom APK on export (adding modules, changing the AndroidManifest.xml, etc.).\nNote that in order to make gradle builds instead of using pre-built APKs, the \"Use Gradle Build\" option should be enabled in the Android export preset."));
	install_android_build_template->set_ok_button_text(TTR("Install"));
	install_android_build_template->connect("confirmed", callable_mp(this, &EditorNode::_menu_confirm_current));