check_valid_responses rejects 4XX and 5XX

[jayvdb]

Describe the bug

cherrybomb/cherrybomb-engine/src/scan/passive/additions_checks.rs

Lines 168 to 193 in c37520a

	pub fn check_valid_responses(&self) -> Vec<Alert> {
	let mut alerts: Vec<Alert> = vec![];
	for (path, item) in &self.swagger.get_paths() {
	for (m, op) in item.get_ops() {
	let statuses = op.responses().keys().cloned().collect::<Vec<String>>();
	for status in statuses {
	if let Ok(res_code) = status.parse::<u16>() {
	if !(100..600).contains(&res_code) {
	alerts.push(Alert::new(
	Level::Low,
	"Responses have an invalid or unrecognized status code",
	format!("swagger path:{path} operation:{m} status:{status}"),
	));
	}
	} else if status != "default" {
	alerts.push(Alert::new(
	Level::Low,
	"Responses have an invalid or unrecognized status code",
	format!("swagger path:{path} operation:{m} status:{status}"),
	));
	}
	}
	}
	}
	alerts
	}

only allows u16 and "default"

https://swagger.io/docs/specification/v3_0/describing-responses/ allows ranges like "4XX"