SDL: audio: Remove an assertion that no longer makes sense.

https://github.com/libsdl-org/SDL/commit/3f4f004794528516a692a8f792ee756346595a29

From 3f4f004794528516a692a8f792ee756346595a29 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Wed, 5 Jul 2023 00:52:28 -0400
Subject: [PATCH] audio: Remove an assertion that no longer makes sense.

One may happen to call SDL_AudioThreadFinalize when thread_alive is not set.
---
 src/audio/SDL_audio.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
index bca3513612d5..5ce08c268453 100644
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@@ -663,7 +663,6 @@ void SDL_QuitAudio(void)
 
 void SDL_AudioThreadFinalize(SDL_AudioDevice *device)
 {
-    SDL_assert(SDL_AtomicGet(&device->thread_alive));
     if (SDL_AtomicGet(&device->condemned)) {
         if (device->thread) {
             SDL_DetachThread(device->thread);  // no one is waiting for us, just detach ourselves.