Runtime fix and code maintenance for vendors

[Birdtalon]

About the pull request

#5066 introduced a runtime in certain vendors when attacking them with anything.
Also removes duplicate attackby() definition.

[2023-12-03 16:04:24.708] runtime error: undefined variable /obj/item/storage/belt/marine/var/token_type
 - proc name: redeem token (/obj/structure/machinery/cm_vending/proc/redeem_token)
 -   source file: code/game/machinery/vending/cm_vending.dm,453
 -   usr: William Henderson (/mob/living/carbon/human)
 -   src: the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep)
 -   usr.loc: the floor (186,73,3) (/turf/open/floor/almayer)
 -   src.loc: the floor (185,73,3) (/turf/open/floor/almayer)
 -   call stack:
 - the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep): redeem token(the M276 pattern ammo load rig (/obj/item/storage/belt/marine), William Henderson (/mob/living/carbon/human))
 - the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep): attackby(the M276 pattern ammo load rig (/obj/item/storage/belt/marine), William Henderson (/mob/living/carbon/human), /list (/list))
 - the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep): attackby(the M276 pattern ammo load rig (/obj/item/storage/belt/marine), William Henderson (/mob/living/carbon/human), /list (/list))
 - William Henderson (/mob/living/carbon/human): click adjacent(the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep), the M276 pattern ammo load rig (/obj/item/storage/belt/marine), /list (/list))
 - William Henderson (/mob/living/carbon/human): do click(the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep), the floor (185,73,3) (/turf/open/floor/almayer), "icon-x=1;icon-y=22;left=1;butt...")
 - ***** (/client): Click(the ColMarTech Surplus Uniform... (/obj/structure/machinery/cm_vending/sorted/uniform_supply/squad_prep), the floor (185,73,3) (/turf/open/floor/almayer), "mapwindow.map", "icon-x=1;icon-y=22;left=1;butt...")

Explain why it's good for the game

Testing Photographs and Procedure

Screenshots & Videos

Put screenshots and videos here with an empty line between the screenshots and the <details> tags.

Changelog

🆑
fix: Fixes a runtime in vendors
/🆑

[realforest2001]

I'm going to be naughty and merge a bit early as it's a bug I introduced & is flooding runtime logs.