### 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)
for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
				Vector<String> r_drivers = DisplayServer::get_create_function_rendering_drivers(i);
				for (int d = 0; d < r_drivers.size(); d++) {
					OS::get_singleton()->print("'%s', ", r_drivers[d].utf8().get_data());
				}
			}
			OS::get_singleton()->print(".\n");
			goto error;
		}
		
		if (rendering_method.is_empty()) {
			if (rendering_driver == "opengl3" || rendering_driver == "opengl3_angle" || rendering_driver == "opengl3_es") {
				rendering_method = "gl_compatibility";
			} else {
				rendering_method = "forward_plus";
			}
		}
		
		bool valid_combination = false;
		Vector<String> available_drivers;
#ifdef VULKAN_ENABLED
		if (rendering_method == "forward_plus" || rendering_method == "mobile") {
			available_drivers.push_back("vulkan");
		}
#endif
#ifdef GLES3_ENABLED
		if (rendering_method == "gl_compatibility") {
			available_drivers.push_back("opengl3");
			available_drivers.push_back("opengl3_angle");
			available_drivers.push_back("opengl3_es");