Janiborgs can no longer use floor buffer for massive speedboost (#20581)

Co-authored-by: adrermail@gmail.com <adrermail@gmail.com>

code/game/objects/items/robot/robot_upgrades.dm

@@ -145,11 +145,16 @@
 	origin_tech = "engineering=4;materials=5;programming=4"
 
 /obj/item/borg/upgrade/vtec/do_install(mob/living/silicon/robot/R)
-	if(R.speed < 0)
+	for(var/obj/item/borg/upgrade/vtec/U in R.contents)
 		to_chat(R, "<span class='notice'>A VTEC unit is already installed!</span>")
 		to_chat(usr, "<span class='notice'>There's no room for another VTEC unit!</span>")
 		return
 
+	for(var/obj/item/borg/upgrade/floorbuffer/U in R.contents)
+		if(R.floorbuffer)
+			R.floorbuffer = FALSE
+			R.speed -= U.buffer_speed
+
 	R.speed = -1 // Gotta go fast.
 
 	return TRUE