### 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)

prop_info.hint_string = export_info.hint_string;
					prop_info.usage = export_info.usage | PROPERTY_USAGE_SCRIPT_VARIABLE;
				} else {
					prop_info.usage = PROPERTY_USAGE_SCRIPT_VARIABLE;
				}
				if (variable->is_static) {
					minfo.index = p_script->static_variables_indices.size();
					p_script->static_variables_indices[name] = minfo;
				} else {
					p_script->member_info[name] = prop_info;
					p_script->member_indices[name] = minfo;
					p_script->members.insert(name);
				}
#ifdef TOOLS_ENABLED
				if (variable->initializer != nullptr && variable->initializer->is_constant) {
					p_script->member_default_values[name] = variable->initializer->reduced_value;
					GDScriptCompiler::convert_to_initializer_type(p_script->member_default_values[name], variable);
				} else {
					p_script->member_default_values.erase(name);
				}
#endif
			} break;
			case GDScriptParser::ClassNode::Member::CONSTANT: {
				const GDScriptParser::ConstantNode *constant = member.constant;
				StringName name = constant->identifier->name;
				p_script->constants.insert(name, constant->initializer->reduced_value);
			} break;
			case GDScriptParser::ClassNode::Member::ENUM_VALUE: {
				const GDScriptParser::EnumNode::Value &enum_value = member.enum_value;
				StringName name = enum_value.identifier->name;