### 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)
if (disable_vsync) {
			window_vsync_mode = DisplayServer::VSyncMode::VSYNC_DISABLED;
		}
	}
	Engine::get_singleton()->set_physics_ticks_per_second(GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "physics/common/physics_ticks_per_second", PROPERTY_HINT_RANGE, "1,1000,1"), 60));
	Engine::get_singleton()->set_max_physics_steps_per_frame(GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "physics/common/max_physics_steps_per_frame", PROPERTY_HINT_RANGE, "1,100,1"), 8));
	Engine::get_singleton()->set_physics_jitter_fix(GLOBAL_DEF("physics/common/physics_jitter_fix", 0.5));
	Engine::get_singleton()->set_max_fps(GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/max_fps", PROPERTY_HINT_RANGE, "0,1000,1"), 0));
	Engine::get_singleton()->set_audio_output_latency(GLOBAL_DEF_RST(PropertyInfo(Variant::INT, "audio/driver/output_latency", PROPERTY_HINT_RANGE, "1,100,1"), 15));
	
	GLOBAL_DEF_RST("audio/driver/output_latency.web", 50);
	GLOBAL_DEF("debug/settings/stdout/print_fps", false);
	GLOBAL_DEF("debug/settings/stdout/print_gpu_profile", false);
	GLOBAL_DEF("debug/settings/stdout/verbose_stdout", false);
	if (!OS::get_singleton()->_verbose_stdout) { 
		OS::get_singleton()->_verbose_stdout = GLOBAL_GET("debug/settings/stdout/verbose_stdout");
	}
#if defined(MACOS_ENABLED) || defined(IOS_ENABLED)
	OS::get_singleton()->set_environment("MVK_CONFIG_LOG_LEVEL", OS::get_singleton()->_verbose_stdout ? "3" : "1"); 
#endif
	if (max_fps >= 0) {
		Engine::get_singleton()->set_max_fps(max_fps);
	}
	if (frame_delay == 0) {
		frame_delay = GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/frame_delay_msec", PROPERTY_HINT_RANGE, "0,100,1,or_greater"), 0);
		if (Engine::get_singleton()->is_editor_hint()) {
			frame_delay = 0;
		}
	}
	if (audio_output_latency >= 1) {