### Godot version

4.0 beta 10

### System information

Windows 10

### Issue description

Godot crashes when i accidently name 2 items in an enum the same

EDIT:
The editor freeze for some seconds, then both editor- and console-window dissapear

### Steps to reproduce

Write

```gdscript
enum {
    A,
}
```

and then add a second line with another A:

```gdscript
enum {
    A,
    A # <- crash
}
```

Does not always immediatly happen if i copy&paste items.
Does not happen when i change the script in another editor and open the script in Godot.

### Minimal reproduction project

[enum.zip](https://github.com/godotengine/godot/files/10313759/enum.zip)

} break;
			case GDScriptParser::ClassNode::Member::CONSTANT: {
				check_class_member_name_conflict(p_class, member.constant->identifier->name, member.constant);
				member.constant->set_datatype(resolving_datatype);
				resolve_constant(member.constant, false);
				
				for (GDScriptParser::AnnotationNode *&E : member.constant->annotations) {
					E->apply(parser, member.constant);
				}
			} break;
			case GDScriptParser::ClassNode::Member::SIGNAL: {
				check_class_member_name_conflict(p_class, member.signal->identifier->name, member.signal);
				member.signal->set_datatype(resolving_datatype);
				
				
				MethodInfo mi = MethodInfo(member.signal->identifier->name);
				for (int j = 0; j < member.signal->parameters.size(); j++) {
					GDScriptParser::ParameterNode *param = member.signal->parameters[j];
					GDScriptParser::DataType param_type = type_from_metatype(resolve_datatype(param->datatype_specifier));
					param->set_datatype(param_type);
					mi.arguments.push_back(PropertyInfo(param_type.builtin_type, param->identifier->name));
					
				}
				member.signal->set_datatype(make_signal_type(mi));
				
				for (GDScriptParser::AnnotationNode *&E : member.signal->annotations) {
					E->apply(parser, member.signal);
				}
			} break;
			case GDScriptParser::ClassNode::Member::ENUM: {