### 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
switch (kind) {
		case VARIANT:
			return "Variant";
		case BUILTIN:
			if (builtin_type == Variant::NIL) {
				return "null";
			}
			if (builtin_type == Variant::ARRAY && has_container_element_type()) {
				return vformat("Array[%s]", container_element_type->to_string());
			}
			return Variant::get_type_name(builtin_type);
		case NATIVE:
			if (is_meta_type) {
				return GDScriptNativeClass::get_class_static();
			}
			return native_type.operator String();
		case CLASS: