### 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)
project_manager = true;
		} else if (I->get() == "--debug-server") {
			if (I->next()) {
				debug_server_uri = I->next()->get();
				if (!debug_server_uri.contains("://")) { 
					OS::get_singleton()->print("Invalid debug server uri. It should be of the form <protocol>://<bind_address>:<port>.\n");
					goto error;
				}
				N = I->next()->next();
			} else {
				OS::get_singleton()->print("Missing remote debug server uri, aborting.\n");
				goto error;
			}
		} else if (I->get() == "--single-threaded-scene") {
			single_threaded_scene = true;
		} else if (I->get() == "--build-solutions") { 
			auto_build_solutions = true;
			editor = true;
			cmdline_tool = true;
		} else if (I->get() == "--dump-gdextension-interface") {
			
			editor = true;
			cmdline_tool = true;
			dump_gdextension_interface = true;
			print_line("Dumping GDExtension interface header file");
			
			
			
			main_args.push_back(I->get());
		} else if (I->get() == "--dump-extension-api") {