### 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
LITERAL,
			MATCH,
			MATCH_BRANCH,
			PARAMETER,
			PASS,
			PATTERN,
			PRELOAD,
			RETURN,
			SELF,
			SIGNAL,
			SUBSCRIPT,
			SUITE,
			TERNARY_OPERATOR,
			TYPE,
			TYPE_TEST,
			UNARY_OPERATOR,
			VARIABLE,
			WHILE,
		};
		Type type = NONE;
		int start_line = 0, end_line = 0;
		int start_column = 0, end_column = 0;
		int leftmost_column = 0, rightmost_column = 0;
		Node *next = nullptr;
		List<AnnotationNode *> annotations;
#ifdef DEBUG_ENABLED
		Vector<GDScriptWarning::Code> ignored_warnings;
#endif
		DataType datatype;
		virtual DataType get_datatype() const { return datatype; }