SDL_mixer: upgrade wavpack (86c30)

From 86c300be59054fba77e33bb33c840c80915e0c4f Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Tue, 5 Sep 2023 23:51:10 +0300
Subject: [PATCH] upgrade wavpack

---
 external/wavpack | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/external/wavpack b/external/wavpack
index 4ca31b02..7578f99b 160000
--- a/external/wavpack
+++ b/external/wavpack
@@ -1 +1 @@
-Subproject commit 4ca31b02865e94858c489c9a86a5f5c84843fc79
+Subproject commit 7578f99b405a74bfc3f4cdd904e22139520b7f12