### 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
ERR_FAIL_COND_V_MSG(p_node->type != Node::FUNCTION, false, vformat(R"("%s" annotation can only be applied to functions.)", p_annotation->name));
	FunctionNode *function = static_cast<FunctionNode *>(p_node);
	if (function->rpc_config.get_type() != Variant::NIL) {
		push_error(R"(RPC annotations can only be used once per function.)", p_annotation);
		return false;
	}
	Dictionary rpc_config;
	rpc_config["rpc_mode"] = MultiplayerAPI::RPC_MODE_AUTHORITY;
	if (p_annotation->resolved_arguments.size()) {
		int last = p_annotation->resolved_arguments.size() - 1;
		if (p_annotation->resolved_arguments[last].get_type() == Variant::INT) {
			rpc_config["channel"] = p_annotation->resolved_arguments[last].operator int();
			last -= 1;
		}
		if (last > 3) {
			push_error(R"(Invalid RPC arguments. At most 4 arguments are allowed, where only the last argument can be an integer to specify the channel.')", p_annotation);
			return false;
		}
		for (int i = last; i >= 0; i--) {
			String mode = p_annotation->resolved_arguments[i].operator String();
			if (mode == "any_peer") {
				rpc_config["rpc_mode"] = MultiplayerAPI::RPC_MODE_ANY_PEER;
			} else if (mode == "authority") {
				rpc_config["rpc_mode"] = MultiplayerAPI::RPC_MODE_AUTHORITY;
			} else if (mode == "call_local") {
				rpc_config["call_local"] = true;
			} else if (mode == "call_remote") {
				rpc_config["call_local"] = false;
			} else if (mode == "reliable") {