### Godot version

v4.0.beta14.official [28a24639c]

### System information

MacOS 12.6.2

### Issue description

Beta 14 throws an error for custom `@icon`, e.g.
```
class_name StateMachine extends Node

@icon("res://assets/icons/state_machine.svg")
```
> Annotation "`@icon`" is not allowed in this level.

In beta 13 and before that worked fine.

### Steps to reproduce

1. Add a custom `@icon` in a custom node script.
2. Error message: Annotation "`@icon`" is not allowed in this level.

There are possibly other errors because a `class_name` node is now not recognized if extended by other classes, but they should resolve if `@icon` is removed.

### Minimal reproduction project

N/A
SubscriptNode *subscript = alloc_node<SubscriptNode>();
	reset_extents(subscript, p_previous_operand);
	update_extents(subscript);
	make_completion_context(COMPLETION_SUBSCRIPT, subscript);
	subscript->base = p_previous_operand;
	subscript->index = parse_expression(false);
	if (subscript->index == nullptr) {
		push_error(R"(Expected expression after "[".)");
	}
	pop_multiline();
	consume(GDScriptTokenizer::Token::BRACKET_CLOSE, R"(Expected "]" after subscription index.)");
	complete_extents(subscript);
	return subscript;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_cast(ExpressionNode *p_previous_operand, bool p_can_assign) {
	CastNode *cast = alloc_node<CastNode>();
	reset_extents(cast, p_previous_operand);
	update_extents(cast);
	cast->operand = p_previous_operand;
	cast->cast_type = parse_type();
	complete_extents(cast);
	if (cast->cast_type == nullptr) {
		push_error(R"(Expected type specifier after "as".)");
		return p_previous_operand;
	}
	return cast;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_call(ExpressionNode *p_previous_operand, bool p_can_assign) {