upgrade vendored wavpack to 5.8.1

sezero · sezero · commit d3428753ea90 · 2025-08-12T00:28:50.000+03:00
diff --git a/.gitmodules b/.gitmodules
@@ -33,7 +33,7 @@
 [submodule "external/wavpack"]
 	path = external/wavpack
 	url = https://github.com/libsdl-org/wavpack.git
-	branch = 5.7.0-sdl
+	branch = 5.8.1-SDL
 [submodule "external/libgme"]
 	path = external/libgme
 	url = https://github.com/libsdl-org/game-music-emu.git
diff --git a/external/wavpack b/external/wavpack
@@ -1 +1 @@
-Subproject commit 1258d38a2ccbed109980a8b7da73181498a5067a
+Subproject commit c9a5393829483f0bb72c1f0bea9042e82c5586e0
