Is it permissible to request an age increase from the guardian (ruler) for retirement without resorting to a medical committee, knowing that this procedure is considered by others to be a form of deception?

As long as a person knows their true age, they are not permitted to declare otherwise, whether they do so themselves or through a committee or an official; all of this is impermissible due to the falsehood involved. If the ruler wishes to grant him retirement based on reasons they possess, there is no objection to that, provided there is no falsehood regarding his age.