make HoS non exclusive to mentors

[Technature]

As an HoS and someone who raids the armory on a semi-normal basis, I kind of have to err on the side of "no". The weapons are nothing to some of the antag gear, but it's terrible enough that a random griefing prick could easily ruin the round for just about everyone with them if not dealt with immediately. And normally I'd agree with the "It's only one round ruined if an admin gets alerted" thing which is an otherwise solid arguement, but security is treated like shit as it is. Having randoms giving people a legitimate reason to hate an already disliked part of the game would be really bad if we want to change that.