[MIRROR] Fixes incorrect operator usage in mecha code (#1920)

* Fixes incorrect operator usage in mecha code (#82570)

## About The Pull Request

I completely screwed up and told the original PR author of #82415
(9922d2f2377c3ab571d34c857174c45f5521a5ae) to use the `XOR` operator
instead of the `OR` operator (I wasn't thinking right for some reason
when I was reading the ref), anyways this PR just fixes that because I
misled the contributor into doing something that wasn't correct and
actually would BREAK functionality instead.

* Fixes incorrect operator usage in mecha code

---------

Co-authored-by: san7890 <[email protected]>

code/modules/vehicles/mecha/_mecha.dm

@@ -272,7 +272,7 @@
 	/// If the former occupants get polymorphed, mutated, chestburstered,
 	/// or otherwise replaced by another mob, that mob is no longer in .occupants
 	/// and gets deleted with the mech. However, they do remain in .contents
-	var/list/potential_occupants = contents ^ occupants
+	var/list/potential_occupants = contents | occupants
 	for(var/mob/buggy_ejectee in potential_occupants)
 		mob_exit(buggy_ejectee, silent = TRUE)