Update SDL3_mixer to 3.2.0

Author: Free-Pascal-meets-SDL-Website

README.md

@@ -49,6 +49,8 @@ The version number/tag (see [tags](https://github.com/PascalGameDevelopment/SDL3
 
 ### v0.x (work in progress)
 
+- updates SDL3_mixer to version 3.2.0
+
 ### v0.5 (15/08/2025)
 
 - adds SDL3_ttf unit