### 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 = ENUM;
		}
	};
	struct ClassNode : public Node {
		struct Member {
			enum Type {
				UNDEFINED,
				CLASS,
				CONSTANT,
				FUNCTION,
				SIGNAL,
				VARIABLE,
				ENUM,
				ENUM_VALUE, 
				GROUP, 
			};
			Type type = UNDEFINED;
			union {
				ClassNode *m_class = nullptr;
				ConstantNode *constant;
				FunctionNode *function;
				SignalNode *signal;
				VariableNode *variable;
				EnumNode *m_enum;
				AnnotationNode *annotation;
			};
			EnumNode::Value enum_value;
			String get_name() const {