SDL_mixer: upgrade vendored libxmp to latest 4.6.1 release (13b37)

From 13b3734a00479b1e5ed088bd649608f280e9a7d1 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Thu, 2 Jan 2025 23:55:32 +0300
Subject: [PATCH] upgrade vendored libxmp to latest 4.6.1 release

---
 .gitmodules     | 2 +-
 external/libxmp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.gitmodules b/.gitmodules
index 258aaf4aa..35b1ed0a6 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -33,7 +33,7 @@
 [submodule "libxmp"]
 	path = external/libxmp
 	url = https://github.com/libsdl-org/libxmp.git
-	branch = 4.6.x-SDL
+	branch = 4.6.1-SDL
 [submodule "external/wavpack"]
 	path = external/wavpack
 	url = https://github.com/libsdl-org/wavpack.git
diff --git a/external/libxmp b/external/libxmp
index f59573ed2..3f0baed2b 160000
--- a/external/libxmp
+++ b/external/libxmp
@@ -1 +1 @@
-Subproject commit f59573ed254d2c5a5b02bac2d2b09a4496d5d6fc
+Subproject commit 3f0baed2bd501a6907850c265e3f70e5f1fc5460