### Godot version

3b086aa06

### System information

ArchLinux x11

### Issue description

```gdscript
extends Node

@export_group("My Properties")
@export var number = 3
@export var string = ""

@export_group("Prefixed Properties", "prefix_")
@export var prefix_number = 3
@export var prefix_string = ""

@export_group("", "")
@export var ungrouped_number = 3
```

![image](https://user-images.githubusercontent.com/70787919/214983963-528c415b-745b-47fc-9777-36ebe31a3060.png)


### Steps to reproduce

- create script
- @export_group
- go inspector

### Minimal reproduction project

‮
return static_cast<LiteralNode *>(parse_literal(nullptr, false));
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_literal(ExpressionNode *p_previous_operand, bool p_can_assign) {
	if (previous.type != GDScriptTokenizer::Token::LITERAL) {
		push_error("Parser bug: parsing literal node without literal token.");
		ERR_FAIL_V_MSG(nullptr, "Parser bug: parsing literal node without literal token.");
	}
	LiteralNode *literal = alloc_node<LiteralNode>();
	complete_extents(literal);
	literal->value = previous.literal;
	return literal;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_self(ExpressionNode *p_previous_operand, bool p_can_assign) {
	if (current_function && current_function->is_static) {
		push_error(R"(Cannot use "self" inside a static function.)");
	}
	SelfNode *self = alloc_node<SelfNode>();
	complete_extents(self);
	self->current_class = current_class;
	return self;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_builtin_constant(ExpressionNode *p_previous_operand, bool p_can_assign) {