### 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
SignalNode *signal = alloc_node<SignalNode>();
	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected signal name after "signal".)")) {
		complete_extents(signal);
		return nullptr;
	}
	signal->identifier = parse_identifier();
	if (check(GDScriptTokenizer::Token::PARENTHESIS_OPEN)) {
		push_multiline(true);
		advance();
		do {
			if (check(GDScriptTokenizer::Token::PARENTHESIS_CLOSE)) {
				
				break;
			}
			ParameterNode *parameter = parse_parameter();
			if (parameter == nullptr) {
				push_error("Expected signal parameter name.");
				break;
			}
			if (parameter->initializer != nullptr) {
				push_error(R"(Signal parameters cannot have a default value.)");
			}