### 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)

if (parsed_classes.has(p_script)) {
		return OK;
	}
	if (parsing_classes.has(p_script)) {
		String class_name = p_class->identifier ? String(p_class->identifier->name) : p_class->fqcn;
		_set_error(vformat(R"(Cyclic class reference for "%s".)", class_name), p_class);
		return ERR_PARSE_ERROR;
	}
	parsing_classes.insert(p_script);
	p_script->clearing = true;
	p_script->native = Ref<GDScriptNativeClass>();
	p_script->base = Ref<GDScript>();
	p_script->_base = nullptr;
	p_script->members.clear();
	
	HashMap<StringName, Variant> constants;
	for (const KeyValue<StringName, Variant> &E : p_script->constants) {
		constants.insert(E.key, E.value);
	}
	p_script->constants.clear();
	constants.clear();
	HashMap<StringName, GDScriptFunction *> member_functions;
	for (const KeyValue<StringName, GDScriptFunction *> &E : p_script->member_functions) {
		member_functions.insert(E.key, E.value);