### 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)
Engine::get_singleton()->set_audio_output_latency(audio_output_latency);
	}
	OS::get_singleton()->set_low_processor_usage_mode(GLOBAL_DEF("application/run/low_processor_mode", false));
	OS::get_singleton()->set_low_processor_usage_mode_sleep_usec(
			GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/low_processor_mode_sleep_usec", PROPERTY_HINT_RANGE, "0,33200,1,or_greater"), 6900)); 
	GLOBAL_DEF("application/run/delta_smoothing", true);
	if (!delta_smoothing_override) {
		OS::get_singleton()->set_delta_smoothing(GLOBAL_GET("application/run/delta_smoothing"));
	}
	GLOBAL_DEF("display/window/ios/allow_high_refresh_rate", true);
	GLOBAL_DEF("display/window/ios/hide_home_indicator", true);
	GLOBAL_DEF("display/window/ios/hide_status_bar", true);
	GLOBAL_DEF("display/window/ios/suppress_ui_gesture", true);
	
	GLOBAL_DEF_RST_BASIC("xr/openxr/enabled", false);
	GLOBAL_DEF_BASIC(PropertyInfo(Variant::STRING, "xr/openxr/default_action_map", PROPERTY_HINT_FILE, "*.tres"), "res://openxr_action_map.tres");
	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/form_factor", PROPERTY_HINT_ENUM, "Head Mounted,Handheld"), "0");
	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/view_configuration", PROPERTY_HINT_ENUM, "Mono,Stereo"), "1"); 
	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/reference_space", PROPERTY_HINT_ENUM, "Local,Stage"), "1");
	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/environment_blend_mode", PROPERTY_HINT_ENUM, "Opaque,Additive,Alpha"), "0");
	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "xr/openxr/foveation_level", PROPERTY_HINT_ENUM, "Off,Low,Medium,High"), "0");
	GLOBAL_DEF_BASIC("xr/openxr/foveation_dynamic", false);
	GLOBAL_DEF_BASIC("xr/openxr/submit_depth_buffer", false);
	GLOBAL_DEF_BASIC("xr/openxr/startup_alert", true);
	
	GLOBAL_DEF_BASIC("xr/openxr/extensions/hand_tracking", true);
	GLOBAL_DEF_BASIC("xr/openxr/extensions/eye_gaze_interaction", false);
#ifdef TOOLS_ENABLED