### 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
CastNode *cast = alloc_node<CastNode>();
	reset_extents(cast, p_previous_operand);
	update_extents(cast);
	cast->operand = p_previous_operand;
	cast->cast_type = parse_type();
	complete_extents(cast);
	if (cast->cast_type == nullptr) {
		push_error(R"(Expected type specifier after "as".)");
		return p_previous_operand;
	}
	return cast;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_call(ExpressionNode *p_previous_operand, bool p_can_assign) {
	CallNode *call = alloc_node<CallNode>();
	reset_extents(call, p_previous_operand);
	if (previous.type == GDScriptTokenizer::Token::SUPER) {
		
		call->is_super = true;
		push_multiline(true);
		if (match(GDScriptTokenizer::Token::PARENTHESIS_OPEN)) {
			
			if (current_function == nullptr) {
				push_error(R"(Cannot use implicit "super" call outside of a function.)");