### 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
return !(this->operator==(p_other));
		}
		void operator=(const DataType &p_other) {
			kind = p_other.kind;
			type_source = p_other.type_source;
			is_read_only = p_other.is_read_only;
			is_constant = p_other.is_constant;
			is_meta_type = p_other.is_meta_type;
			is_pseudo_type = p_other.is_pseudo_type;
			is_coroutine = p_other.is_coroutine;
			builtin_type = p_other.builtin_type;
			native_type = p_other.native_type;
			enum_type = p_other.enum_type;
			script_type = p_other.script_type;
			script_path = p_other.script_path;
			class_type = p_other.class_type;
			method_info = p_other.method_info;
			enum_values = p_other.enum_values;
			unset_container_element_type();
			if (p_other.has_container_element_type()) {
				set_container_element_type(p_other.get_container_element_type());
			}
		}
		DataType() = default;