### Godot version

v4.0.3.stable.official [5222a99f5]
Master [6101240231600c871f5c5473872532c68ea3268c] (confirmed by https://github.com/godotengine/godot/issues/77666#issuecomment-1568952502)

### System information

Window 10

### Issue description

References are not unreferenced at the end of `if` scopes.

### Steps to reproduce

Copy, paste and run the snippet below, check the results:

```gdscript
extends Node


func _ready() -> void:
  var ref := RefCounted.new()
  var ref_count : int

  # OK
  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)

  # OK
  if true:
    var temp := ref
    temp = null

  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)

  # FAIL
  if true:
    var temp := ref

  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)
```

Output example:

```
Expected: 1, Result: 1
Expected: 1, Result: 1
Expected: 1, Result: 2
```

### Minimal reproduction project

N/A
type->type_chain.push_back(type_element);
	if (match(GDScriptTokenizer::Token::BRACKET_OPEN)) {
		
		type->container_type = parse_type(false); 
		if (type->container_type == nullptr) {
			push_error(R"(Expected type for collection after "[".)");
			complete_extents(type);
			type = nullptr;
		} else if (type->container_type->container_type != nullptr) {
			push_error("Nested typed collections are not supported.");
		}
		consume(GDScriptTokenizer::Token::BRACKET_CLOSE, R"(Expected closing "]" after collection type.)");
		if (type != nullptr) {
			complete_extents(type);
		}
		return type;
	}
	int chain_index = 1;
	while (match(GDScriptTokenizer::Token::PERIOD)) {
		make_completion_context(COMPLETION_TYPE_ATTRIBUTE, type, chain_index++);
		if (consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected inner type name after ".".)")) {
			type_element = parse_identifier();
			type->type_chain.push_back(type_element);
		}
	}
	complete_extents(type);
	return type;
}
#ifdef TOOLS_ENABLED
enum DocLineState {