### 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

‮
ConstantNode *constant = alloc_node<ConstantNode>();
	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected constant name after "const".)")) {
		return nullptr;
	}
	constant->identifier = parse_identifier();
	if (match(GDScriptTokenizer::Token::COLON)) {
		if (check((GDScriptTokenizer::Token::EQUAL))) {
			
			constant->infer_datatype = true;
		} else {
			
			constant->datatype_specifier = parse_type();
		}
	}
	if (consume(GDScriptTokenizer::Token::EQUAL, R"(Expected initializer after constant name.)")) {
		
		constant->initializer = parse_expression(false);
		if (constant->initializer == nullptr) {
			push_error(R"(Expected initializer expression for constant.)");
			complete_extents(constant);
			return nullptr;
		}
	} else {
		complete_extents(constant);