### 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 (p_method->is_vararg()) {
		
		return false;
	}
	if (p_method->get_argument_count() != p_arguments.size()) {
		
		return false;
	}
	MethodInfo info;
	ClassDB::get_method_info(p_method->get_instance_class(), p_method->get_name(), &info);
	for (int i = 0; i < p_arguments.size(); i++) {
		const PropertyInfo &prop = info.arguments[i];
		if (!_is_exact_type(prop, p_arguments[i].type)) {
			return false;
		}
	}
	return true;
}
GDScriptCodeGenerator::Address GDScriptCompiler::_parse_expression(CodeGen &codegen, Error &r_error, const GDScriptParser::ExpressionNode *p_expression, bool p_root, bool p_initializer, const GDScriptCodeGenerator::Address &p_index_addr) {
	if (p_expression->is_constant && !(p_expression->get_datatype().is_meta_type && p_expression->get_datatype().kind == GDScriptParser::DataType::CLASS)) {
		return codegen.add_constant(p_expression->reduced_value);