Makes deadchat control's examine only shows up for ghosts (#57926)

This PR early returns the on_examine proc for deadchat control if the examiner is not an observer.
So, only ghosts (deadchat) are allowed to see if something is under deadchat control. Humans don't need to know (or shouldn't know) if deadchat is expanding its reach into the physical realm.

code/datums/components/deadchat_control.dm

@@ -157,6 +157,9 @@
 /datum/component/deadchat_control/proc/on_examine(atom/A, mob/user, list/examine_list)
 	SIGNAL_HANDLER
 
+	if(!isobserver(user))
+		return
+
 	examine_list += "<span class='notice'>[A.p_theyre(TRUE)] currently under deadchat control using the [deadchat_mode] ruleset!</span>"
 
 	if(deadchat_mode == DEMOCRACY_MODE)