### 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 (Object::cast_to<Script>(*p_resource)) {
		return memnew(ScriptTextEditor);
	}
	return nullptr;
}
void ScriptTextEditor::register_editor() {
	ED_SHORTCUT("script_text_editor/move_up", TTR("Move Up"), KeyModifierMask::ALT | Key::UP);
	ED_SHORTCUT("script_text_editor/move_down", TTR("Move Down"), KeyModifierMask::ALT | Key::DOWN);
	ED_SHORTCUT("script_text_editor/delete_line", TTR("Delete Line"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::K);
	
	
	ED_SHORTCUT("script_text_editor/indent", TTR("Indent"), Key::NONE);
	ED_SHORTCUT("script_text_editor/unindent", TTR("Unindent"), KeyModifierMask::SHIFT | Key::TAB);
	ED_SHORTCUT_ARRAY("script_text_editor/toggle_comment", TTR("Toggle Comment"), { int32_t(KeyModifierMask::CMD_OR_CTRL | Key::K), int32_t(KeyModifierMask::CMD_OR_CTRL | Key::SLASH) });
	ED_SHORTCUT("script_text_editor/toggle_fold_line", TTR("Fold/Unfold Line"), KeyModifierMask::ALT | Key::F);
	ED_SHORTCUT_OVERRIDE("script_text_editor/toggle_fold_line", "macos", KeyModifierMask::CTRL | KeyModifierMask::META | Key::F);
	ED_SHORTCUT("script_text_editor/fold_all_lines", TTR("Fold All Lines"), Key::NONE);
	ED_SHORTCUT("script_text_editor/create_code_region", TTR("Create Code Region"), KeyModifierMask::ALT | Key::R);
	ED_SHORTCUT("script_text_editor/unfold_all_lines", TTR("Unfold All Lines"), Key::NONE);
	ED_SHORTCUT("script_text_editor/duplicate_selection", TTR("Duplicate Selection"), KeyModifierMask::SHIFT | KeyModifierMask::CTRL | Key::D);
	ED_SHORTCUT_OVERRIDE("script_text_editor/duplicate_selection", "macos", KeyModifierMask::SHIFT | KeyModifierMask::META | Key::C);
	ED_SHORTCUT("script_text_editor/duplicate_lines", TTR("Duplicate Lines"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | Key::DOWN);
	ED_SHORTCUT_OVERRIDE("script_text_editor/duplicate_lines", "macos", KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::DOWN);
	ED_SHORTCUT("script_text_editor/evaluate_selection", TTR("Evaluate Selection"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::E);
	ED_SHORTCUT("script_text_editor/toggle_word_wrap", TTR("Toggle Word Wrap"), KeyModifierMask::ALT | Key::Z);
	ED_SHORTCUT("script_text_editor/trim_trailing_whitespace", TTR("Trim Trailing Whitespace"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | Key::T);
	ED_SHORTCUT("script_text_editor/convert_indent_to_spaces", TTR("Convert Indent to Spaces"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::Y);
	ED_SHORTCUT("script_text_editor/convert_indent_to_tabs", TTR("Convert Indent to Tabs"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::I);