### 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)
BLOCK_DEVICE("ATI", "AMD Radeon(TM) R2 Graphics");
		BLOCK_DEVICE("ATI", "AMD Radeon(TM) R3 Graphics");
		BLOCK_DEVICE("ATI", "AMD Radeon HD 8400 / R3 Series");
		BLOCK_DEVICE("ATI", "AMD Radeon R5 M200 Series");
		BLOCK_DEVICE("ATI", "AMD Radeon R5 M230 Series");
		BLOCK_DEVICE("ATI", "AMD Radeon R5 M255");
		BLOCK_DEVICE("AMD", "AMD Radeon (TM) R5 M330");
#undef BLOCK_DEVICE
		GLOBAL_DEF_RST_NOVAL(PropertyInfo(Variant::ARRAY, "rendering/gl_compatibility/force_angle_on_devices", PROPERTY_HINT_ARRAY_TYPE, vformat("%s/%s:%s", Variant::DICTIONARY, PROPERTY_HINT_NONE, String())), device_blocklist);
	}
	
#ifdef VULKAN_ENABLED
	renderer_hints = "forward_plus,mobile";
	default_renderer_mobile = "mobile";
#endif
	
#ifdef GLES3_ENABLED
	if (!renderer_hints.is_empty()) {
		renderer_hints += ",";
	}
	renderer_hints += "gl_compatibility";
	if (default_renderer_mobile.is_empty()) {
		default_renderer_mobile = "gl_compatibility";
	}
	
	if (rendering_driver.is_empty() && rendering_method.is_empty() && project_manager) {
		rendering_driver = "opengl3";
		rendering_method = "gl_compatibility";
		default_renderer_mobile = "gl_compatibility";