### 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
if (found) {
				break;
			}
			cursor_line++;
			cursor_column = 1;
		}
		source = source.replace_first(String::chr(0xFFFF), String());
	}
	tokenizer.set_source_code(source);
	tokenizer.set_cursor_position(cursor_line, cursor_column);
	script_path = p_script_path;
	current = tokenizer.scan();
	
	
	while (current.type == GDScriptTokenizer::Token::ERROR || current.type == GDScriptTokenizer::Token::NEWLINE) {
		if (current.type == GDScriptTokenizer::Token::ERROR) {
			push_error(current.literal);
		}
		current = tokenizer.scan();
	}
#ifdef DEBUG_ENABLED
	
	if (current.type == GDScriptTokenizer::Token::TK_EOF) {
		
		Node *nd = alloc_node<PassNode>();
		nd->start_line = 1;
		nd->start_column = 0;
		nd->end_line = 1;
		nd->leftmost_column = 0;
		nd->rightmost_column = 0;