### 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
if (in_lambda) {
					
					lambda_ended = true;
					has_ended_lambda = true;
				} else {
					advance();
					push_error(vformat(R"(Expected statement, found "%s" instead.)", previous.get_name()));
				}
			} else {
				end_statement("expression");
			}
			lambda_ended = lambda_ended || has_ended_lambda;
			result = expression;
#ifdef DEBUG_ENABLED
			if (expression != nullptr) {
				switch (expression->type) {
					case Node::CALL:
					case Node::ASSIGNMENT:
					case Node::AWAIT:
						
						break;
					case Node::LAMBDA:
						
						push_error("Standalone lambdas cannot be accessed. Consider assigning it to a variable.", expression);
						break;
					default:
						push_warning(expression, GDScriptWarning::STANDALONE_EXPRESSION);
				}
			}
#endif