### 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
ConstantNode *constant = alloc_node<ConstantNode>();
	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected constant name after "const".)")) {
		return nullptr;
	}
	constant->identifier = parse_identifier();
	if (match(GDScriptTokenizer::Token::COLON)) {
		if (check((GDScriptTokenizer::Token::EQUAL))) {
			
			constant->infer_datatype = true;
		} else {
			
			constant->datatype_specifier = parse_type();
		}
	}
	if (consume(GDScriptTokenizer::Token::EQUAL, R"(Expected initializer after constant name.)")) {
		
		constant->initializer = parse_expression(false);
		if (constant->initializer == nullptr) {
			push_error(R"(Expected initializer expression for constant.)");
			complete_extents(constant);
			return nullptr;
		}
	} else {
		complete_extents(constant);