add option to disable end of round sound (#26014)

* add option to disable end of round sound

* fix sleep position

* add EOR sound to enable/disable preferences

* invert logic so that existing players don't mute the sound

* fix inconsistent mute/hear variable

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Co-authored-by: pwbokie <pmerkamp@butler.edu>

code/modules/client/preference/link_processing.dm

@@ -1053,6 +1053,9 @@
 				if("hear_midis")
 					sound ^= SOUND_MIDI
 
+				if("mute_end_of_round")
+					sound ^= SOUND_MUTE_END_OF_ROUND
+
 				if("lobby_music")
 					sound ^= SOUND_LOBBY
 					if((sound & SOUND_LOBBY) && user.client)