### 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 GDScriptCodeGenerator::Address();
			}
			gen->write_ternary_true_expr(true_expr);
			if (true_expr.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
				gen->pop_temporary();
			}
			GDScriptCodeGenerator::Address false_expr = _parse_expression(codegen, r_error, ternary->false_expr);
			if (r_error) {
				return GDScriptCodeGenerator::Address();
			}
			gen->write_ternary_false_expr(false_expr);
			if (false_expr.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
				gen->pop_temporary();
			}
			gen->write_end_ternary();
			return result;
		} break;
		case GDScriptParser::Node::TYPE_TEST: {
			const GDScriptParser::TypeTestNode *type_test = static_cast<const GDScriptParser::TypeTestNode *>(p_expression);
			GDScriptCodeGenerator::Address result = codegen.add_temporary(_gdtype_from_datatype(type_test->get_datatype(), codegen.script));
			GDScriptCodeGenerator::Address operand = _parse_expression(codegen, r_error, type_test->operand);
			GDScriptDataType test_type = _gdtype_from_datatype(type_test->test_datatype, codegen.script);
			if (r_error) {
				return GDScriptCodeGenerator::Address();
			}
			if (test_type.has_type) {
				gen->write_type_test(result, operand, test_type);
			} else {
				gen->write_assign_true(result);
			}