### Godot version

4.0-rc1

### System information

Windows 10

### Issue description

The code: `@export @onready var camera_system : Node3D`

Is throwing: `Line 5:The "@onready" annotation will make the default value to be set after the "@export" takes effect and will override it. (Warning treated as error.)` and is crashing the game.

Unchecking "Treat Warning as Errors" seems to have no effect:

![imagen](https://user-images.githubusercontent.com/248383/217900756-8e214c40-68fb-4fb2-8509-a1e689725930.png)

![imagen](https://user-images.githubusercontent.com/248383/217901253-3b758ebc-48e9-40fe-8d77-16fce7cbae88.png)


### Steps to reproduce

- Write `@export @onready var some_var : Node3D`
- In Project Settings, uncheck `Treat Warning as Errors`
- Try to run the project, a `Parser Error` will be thrown.

### Minimal reproduction project

It's as simple as adding one line of code, so I'm not sure a MRP is needed.
assignment->assignee = p_previous_operand;
	assignment->assigned_value = parse_expression(false);
	if (assignment->assigned_value == nullptr) {
		push_error(R"(Expected an expression after "=".)");
	}
	complete_extents(assignment);
#ifdef DEBUG_ENABLED
	if (source_variable != nullptr) {
		if (has_operator && source_variable->assignments == 0) {
			push_warning(assignment, GDScriptWarning::UNASSIGNED_VARIABLE_OP_ASSIGN, source_variable->identifier->name);
		}
		source_variable->assignments += 1;
	}
#endif
	return assignment;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_await(ExpressionNode *p_previous_operand, bool p_can_assign) {
	AwaitNode *await = alloc_node<AwaitNode>();
	ExpressionNode *element = parse_precedence(PREC_AWAIT, false);
	if (element == nullptr) {
		push_error(R"(Expected signal or coroutine after "await".)");
	}
	await->to_await = element;
	complete_extents(await);
	if (current_function) { 
		current_function->is_coroutine = true;
	}
	return await;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_array(ExpressionNode *p_previous_operand, bool p_can_assign) {