### 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)
HashMap<NodePath, ModificationNodeEntry> modification_table;
				List<AdditiveNodeEntry> addition_list;
				update_diff_data_for_node(current_edited_scene, original_node, original_node, modification_table, addition_list);
				
				for (const KeyValue<NodePath, ModificationNodeEntry> &modification_table_entry : modification_table) {
					for (Connection conn : modification_table_entry.value.connections_from) {
						conn.signal.get_object()->disconnect(conn.signal.get_name(), conn.callable);
					}
					for (ConnectionWithNodePath cwnp : modification_table_entry.value.connections_to) {
						Connection conn = cwnp.connection;
						if (conn.flags & CONNECT_PERSIST) {
							conn.signal.get_object()->disconnect(conn.signal.get_name(), conn.callable);
						}
					}
				}
				
				List<NodePath> selected_node_paths;
				for (Node *selected_node : editor_selection->get_selected_node_list()) {
					if (selected_node == original_node || original_node->is_ancestor_of(selected_node)) {
						selected_node_paths.push_back(original_node->get_path_to(selected_node));
						editor_selection->remove_node(selected_node);
					}
				}
				
				for (AdditiveNodeEntry additive_node_entry : addition_list) {
					Node *addition_node = additive_node_entry.node;
					addition_node->get_parent()->remove_child(addition_node);
				}