Stop the sound cues from completed games

This is usually only an issue with high latency or multi-player AI games, but sound cues will always play in their entirety and in order. If you get enough of them stacked up, they'll keep playing long after the game that triggered them is over (and delaying any sound cues from your new game(s) until they finish). Ideally, sound cues from a completed game should be ignored and tossed out without being played.

An easy way to reproduce this is to start a three player game with two AIs and decks that enable them to attack repeatedly - I used 40 Black Lotus, 20 Atris, Oracle of Half-Truths - then concede the game. The two AIs play out the remainder on hyper-speed, stacking up sound commands for attacking and turn passing to the point where - even after the game ends - there's a solid minute or two of sound cues going off.