### 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
push_error(vformat(R"(Parameter with name "%s" was already declared for this %s.)", parameter->identifier->name, p_type));
			} else {
				p_function->parameters_indices[parameter->identifier->name] = p_function->parameters.size();
				p_function->parameters.push_back(parameter);
				p_body->add_local(parameter, current_function);
			}
		} while (match(GDScriptTokenizer::Token::COMMA));
	}
	pop_multiline();
	consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, vformat(R"*(Expected closing ")" after %s parameters.)*", p_type));
	if (match(GDScriptTokenizer::Token::FORWARD_ARROW)) {
		make_completion_context(COMPLETION_TYPE_NAME_OR_VOID, p_function);
		p_function->return_type = parse_type(true);
		if (p_function->return_type == nullptr) {
			push_error(R"(Expected return type or "void" after "->".)");
		}
	}
	if (!p_function->source_lambda && p_function->identifier && p_function->identifier->name == GDScriptLanguage::get_singleton()->strings._static_init) {
		if (!p_function->is_static) {
			push_error(R"(Static constructor must be declared static.)");
		}
		if (p_function->parameters.size() != 0) {
			push_error(R"(Static constructor cannot have parameters.)");
		}
		current_class->has_static_data = true;
	}
	
	consume(GDScriptTokenizer::Token::COLON, vformat(R"(Expected ":" after %s declaration.)", p_type));
}
GDScriptParser::FunctionNode *GDScriptParser::parse_function(bool p_is_static) {