### Godot version

4.1.0

### System information

Windows 10, i711800H, Forward+ Vulkan

### Issue description

When using @export_group("Name") in a BaseClass, then inheriting from that BaseClass in another class and there also using @export_group("Name"), with the same group name, then running the project and re-saving the inherited class the project crashes with 
```
ERROR: FATAL: Index p_index = 3 is out of bounds (size() = 3).
   at: get (./core/templates/cowdata.h:155)
```

sometimes the editor crashes too after a while.

### Steps to reproduce

1. open reproduction project
2. Run the project.
3. Open the "super"script
4. Press CTRL + S to save it.

### Minimal reproduction project

[MRP_.zip](https://github.com/godotengine/godot/files/12137412/MRP_.zip)

return err;
		}
	}
#ifdef DEBUG_ENABLED
	
	if (p_keep_state) {
		for (RBSet<Object *>::Element *E = p_script->instances.front(); E;) {
			RBSet<Object *>::Element *N = E->next();
			ScriptInstance *si = E->get()->get_script_instance();
			if (si->is_placeholder()) {
#ifdef TOOLS_ENABLED
				PlaceHolderScriptInstance *psi = static_cast<PlaceHolderScriptInstance *>(si);
				if (p_script->is_tool()) {
					
					p_script->placeholders.erase(psi); 
					GDScriptInstance *instance = memnew(GDScriptInstance);
					instance->base_ref_counted = Object::cast_to<RefCounted>(E->get());
					instance->members.resize(p_script->member_indices.size());
					instance->script = Ref<GDScript>(p_script);
					instance->owner = E->get();
					
					for (const KeyValue<StringName, GDScript::MemberInfo> &F : p_script->member_indices) {
						instance->member_indices_cache[F.key] = F.value.index;
					}
					instance->owner->set_script_instance(instance);
					
					Callable::CallError ce;
					p_script->initializer->call(instance, nullptr, 0, ce);
					if (ce.error != Callable::CallError::CALL_OK) {