### 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
GDScriptTokenizer::Token::Type op_type = previous.type;
	LiteralNode *constant = alloc_node<LiteralNode>();
	complete_extents(constant);
	switch (op_type) {
		case GDScriptTokenizer::Token::CONST_PI:
			constant->value = Math_PI;
			break;
		case GDScriptTokenizer::Token::CONST_TAU:
			constant->value = Math_TAU;
			break;
		case GDScriptTokenizer::Token::CONST_INF:
			constant->value = INFINITY;
			break;
		case GDScriptTokenizer::Token::CONST_NAN:
			constant->value = NAN;
			break;
		default:
			return nullptr; 
	}
	return constant;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_unary_operator(ExpressionNode *p_previous_operand, bool p_can_assign) {