### 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
const HashSet<int> &get_unsafe_lines() const { return unsafe_lines; }
	int get_last_line_number() const { return current.end_line; }
#endif
	GDScriptParser();
	~GDScriptParser();
#ifdef DEBUG_ENABLED
	class TreePrinter {
		int indent_level = 0;
		String indent;
		StringBuilder printed;
		bool pending_indent = false;
		void increase_indent();
		void decrease_indent();
		void push_line(const String &p_line = String());
		void push_text(const String &p_text);
		void print_annotation(const AnnotationNode *p_annotation);
		void print_array(ArrayNode *p_array);
		void print_assert(AssertNode *p_assert);
		void print_assignment(AssignmentNode *p_assignment);
		void print_await(AwaitNode *p_await);
		void print_binary_op(BinaryOpNode *p_binary_op);
		void print_call(CallNode *p_call);
		void print_cast(CastNode *p_cast);
		void print_class(ClassNode *p_class);
		void print_constant(ConstantNode *p_constant);
		void print_dictionary(DictionaryNode *p_dictionary);
		void print_expression(ExpressionNode *p_expression);
		void print_enum(EnumNode *p_enum);
		void print_for(ForNode *p_for);
		void print_function(FunctionNode *p_function, const String &p_context = "Function");