Fix printer handout runtime (#21637)

# Summary

This PR fixes a runtime when printers eject paper without a mob being
nearby (mainly automated console printouts).

## Changes

- Add mob check when printer handout papers.

code/modules/modular_computers/hardware/nano_printer.dm

@@ -29,7 +29,8 @@
 		P.color = paper_color
 
 	stored_paper--
-	usr.put_in_hands(P, TRUE)
+	if(ismob(usr))
+		usr.put_in_hands(P, TRUE)
 	return P
 
 /obj/item/computer_hardware/nano_printer/attackby(obj/item/attacking_item, mob/user)

html/changelogs/fabiank3-fix-printer-handout.yml

@@ -0,0 +1,6 @@
+author: FabianK3
+
+delete-after: True
+
+changes:
+  - bugfix: "Fixed runtime error when paper is handed out by printers without a mob nearby."