### 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
push_warning(nd, GDScriptWarning::EMPTY_FILE);
	}
#endif
	push_multiline(false); 
	parse_program();
	pop_multiline();
#ifdef DEBUG_ENABLED
	if (multiline_stack.size() > 0) {
		ERR_PRINT("Parser bug: Imbalanced multiline stack.");
	}
#endif
	if (errors.is_empty()) {
		return OK;
	} else {
		return ERR_PARSE_ERROR;
	}
}
GDScriptTokenizer::Token GDScriptParser::advance() {
	lambda_ended = false; 
	if (current.type == GDScriptTokenizer::Token::TK_EOF) {
		ERR_FAIL_COND_V_MSG(current.type == GDScriptTokenizer::Token::TK_EOF, current, "GDScript parser bug: Trying to advance past the end of stream.");
	}
	if (for_completion && !completion_call_stack.is_empty()) {
		if (completion_call.call == nullptr && tokenizer.is_past_cursor()) {
			completion_call = completion_call_stack.back()->get();
			passed_cursor = true;
		}
	}
	previous = current;
	current = tokenizer.scan();