Removes obsolete check in update_revive (thus fixing SR revival of people dead to tox) (#17907)

* Make SR usable for reviving people dead to tox

* Remove effectively-unreachable drone can_be_revive override

code/modules/mob/living/silicon/robot/drone/drone.dm

@@ -128,11 +128,6 @@
 /mob/living/silicon/robot/drone/pick_module()
 	return
 
-/mob/living/silicon/robot/drone/can_be_revived()
-	. = ..()
-	if(emagged)
-		return FALSE
-
 /mob/living/silicon/robot/drone/detailed_examine()
 	return "Drones are player-controlled synthetics which are lawed to maintain the station and not \
 			interact with anyone else, except for other drones. They hold a wide array of tools to build, repair, maintain, and clean. \

code/modules/mob/living/stat_states.dm

@@ -33,26 +33,18 @@
 		update_canmove()
 	return 1
 
-/mob/living/proc/can_be_revived()
-	. = TRUE
-	// if(health <= min_health)
-	if(health <= HEALTH_THRESHOLD_DEAD)
-		return FALSE
-
 // death() is used to make a mob die
 
 // handles revival through other means than cloning or adminbus (defib, IPC repair)
 /mob/living/proc/update_revive(updating = TRUE)
 	if(stat != DEAD)
 		return 0
-	if(!can_be_revived())
-		return 0
 	create_attack_log("<font color='red'>Came back to life at [atom_loc_line(get_turf(src))]</font>")
 	add_attack_logs(src, null, "Came back to life", ATKLOG_ALL)
 	log_game("[key_name(src)] came back to life at [atom_loc_line(get_turf(src))]")
 	stat = CONSCIOUS
 	GLOB.dead_mob_list -= src
-	GLOB.alive_mob_list += src
+	GLOB.alive_mob_list |= src
 	if(mind)
 		remove_from_respawnable_list()
 	timeofdeath = null