### 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
BRIEF,
		DESC,
		TUTORIALS,
		DONE,
	};
	Mode mode = BRIEF;
	if (p_inner_class) {
		while (comments.has(line - 1)) {
			if (!comments[line - 1].new_line || !comments[line - 1].comment.begins_with("##")) {
				break;
			}
			line--;
		}
	}
	int codeblock_begins = 0;
	while (comments.has(line)) {
		if (!comments[line].new_line || !comments[line].comment.begins_with("##")) {
			break;
		}
		String title, link; 
		String doc_line = comments[line++].comment.trim_prefix("##");
		String stripped_line = doc_line.strip_edges();
		
		if (stripped_line.is_empty() && mode == BRIEF && !p_brief.is_empty()) {
			mode = DESC;
			continue;
		} else if (stripped_line.begins_with("@tutorial")) {