### 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
DictionaryNode *dictionary = alloc_node<DictionaryNode>();
	bool decided_style = false;
	if (!check(GDScriptTokenizer::Token::BRACE_CLOSE)) {
		do {
			if (check(GDScriptTokenizer::Token::BRACE_CLOSE)) {
				
				break;
			}
			
			ExpressionNode *key = parse_expression(false, true); 
			if (key == nullptr) {
				push_error(R"(Expected expression as dictionary key.)");
			}
			if (!decided_style) {
				switch (current.type) {
					case GDScriptTokenizer::Token::COLON:
						dictionary->style = DictionaryNode::PYTHON_DICT;
						break;
					case GDScriptTokenizer::Token::EQUAL:
						dictionary->style = DictionaryNode::LUA_TABLE;
						break;
					default:
						push_error(R"(Expected ":" or "=" after dictionary key.)");