### 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
PreloadNode *preload = alloc_node<PreloadNode>();
	preload->resolved_path = "<missing path>";
	push_multiline(true);
	consume(GDScriptTokenizer::Token::PARENTHESIS_OPEN, R"(Expected "(" after "preload".)");
	make_completion_context(COMPLETION_RESOURCE_PATH, preload);
	push_completion_call(preload);
	preload->path = parse_expression(false);
	if (preload->path == nullptr) {
		push_error(R"(Expected resource path after "(".)");
	}
	pop_completion_call();
	pop_multiline();
	consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, R"*(Expected ")" after preload path.)*");
	complete_extents(preload);
	return preload;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_lambda(ExpressionNode *p_previous_operand, bool p_can_assign) {
	LambdaNode *lambda = alloc_node<LambdaNode>();
	lambda->parent_function = current_function;
	FunctionNode *function = alloc_node<FunctionNode>();
	function->source_lambda = lambda;
	function->is_static = current_function != nullptr ? current_function->is_static : false;
	if (match(GDScriptTokenizer::Token::IDENTIFIER)) {
		function->identifier = parse_identifier();
	}
	bool multiline_context = multiline_stack.back()->get();
	
	push_multiline(false);
	if (multiline_context) {
		tokenizer.push_expression_indented_block();