### 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 (export_preset.is_null()) {
			Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
			if (da->file_exists("res:export_presets.cfg")) {
				err = FAILED;
				export_error = vformat(
						"Invalid export preset name: %s.\nThe following presets were detected in this project's `export_presets.cfg`:\n\n",
						preset_name);
				for (int i = 0; i < EditorExport::get_singleton()->get_export_preset_count(); ++i) {
					
					export_error += vformat("        \"%s\"\n", EditorExport::get_singleton()->get_export_preset(i)->get_name());
				}
			} else {
				err = FAILED;
				export_error = "This project doesn't have an `export_presets.cfg` file at its root.\nCreate an export preset from the \"Project > Export\" dialog and try again.";
			}
		} else {
			Ref<EditorExportPlatform> platform = export_preset->get_platform();
			const String export_path = export_defer.path.is_empty() ? export_preset->get_export_path() : export_defer.path;
			if (export_path.is_empty()) {
				err = FAILED;
				export_error = vformat("Export preset \"%s\" doesn't have a default export path, and none was specified.", preset_name);
			} else if (platform.is_null()) {
				err = FAILED;
				export_error = vformat("Export preset \"%s\" doesn't have a matching platform.", preset_name);
			} else {
				if (export_defer.pack_only) { 
					if (export_path.ends_with(".zip")) {
						err = platform->export_zip(export_preset, export_defer.debug, export_path);
					} else if (export_path.ends_with(".pck")) {