### 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
if (info.name == identifier->name) {
						push_warning(identifier, GDScriptWarning::SHADOWED_GLOBAL_IDENTIFIER, "enum member", identifier->name, "built-in function");
					}
				}
				if (Variant::has_utility_function(identifier->name)) {
					push_warning(identifier, GDScriptWarning::SHADOWED_GLOBAL_IDENTIFIER, "enum member", identifier->name, "built-in function");
				} else if (ClassDB::class_exists(identifier->name)) {
					push_warning(identifier, GDScriptWarning::SHADOWED_GLOBAL_IDENTIFIER, "enum member", identifier->name, "global class");
				}
			}
#endif
			item.identifier = identifier;
			item.parent_enum = enum_node;
			item.line = previous.start_line;
			item.leftmost_column = previous.leftmost_column;
			item.rightmost_column = previous.rightmost_column;
			if (elements.has(item.identifier->name)) {
				push_error(vformat(R"(Name "%s" was already in this enum (at line %d).)", item.identifier->name, elements[item.identifier->name]), item.identifier);
			} else if (!named) {
				if (current_class->members_indices.has(item.identifier->name)) {
					push_error(vformat(R"(Name "%s" is already used as a class %s.)", item.identifier->name, current_class->get_member(item.identifier->name).get_type_name()));
				}
			}
			elements[item.identifier->name] = item.line;
			if (match(GDScriptTokenizer::Token::EQUAL)) {
				ExpressionNode *value = parse_expression(false);
				if (value == nullptr) {
					push_error(R"(Expected expression value after "=".)");
				}
				item.custom_value = value;