### 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)

GDScriptCodeGenerator::Address assigned = _parse_expression(codegen, r_error, assignment->assigned_value);
				if (r_error) {
					return GDScriptCodeGenerator::Address();
				}
				
				GDScriptCodeGenerator::Address key;
				StringName name;
				if (subscript->is_attribute) {
					name = subscript->attribute->name;
				} else {
					key = _parse_expression(codegen, r_error, subscript->index);
					if (r_error) {
						return GDScriptCodeGenerator::Address();
					}
				}
				
				if (assignment->operation != GDScriptParser::AssignmentNode::OP_NONE) {
					GDScriptCodeGenerator::Address op_result = codegen.add_temporary(_gdtype_from_datatype(assignment->get_datatype(), codegen.script));
					GDScriptCodeGenerator::Address value = codegen.add_temporary(_gdtype_from_datatype(subscript->get_datatype(), codegen.script));
					if (subscript->is_attribute) {
						gen->write_get_named(value, name, prev_base);
					} else {
						gen->write_get(value, key, prev_base);
					}
					gen->write_binary_operator(op_result, assignment->variant_op, value, assigned);
					gen->pop_temporary();
					if (assigned.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
						gen->pop_temporary();
					}