Fixes duplicating items with vendors

[VileBeggar]

About the pull request

stops players from being able to duplicate items with vendors
fixes #6475

Explain why it's good for the game

bugs are bad. i don't think this bug actually resulted in much of a benefit because the glitched items were very buggy

Testing Photographs and Procedure

Screenshots & Videos

tested restocking items from the inventory too, and it works

Attachment.Ifx.mp4

Changelog

🆑
fix: You can no longer duplicate items with vendors.
/:cl:

[Drulikar]

This isn't really a solution to the cited bug because you can still say tactical reload a mag into the vendor, and then its free ammo. Try instead preventing vendor restock if the user is busy instead.

However, restocking guns maybe shouldn't be a thing regardless unless attachments are restored to their stock state. So disabling guns going back into the vendor is okay unless you want to perform additional checks on the gun to ensure it is in its stock state.