community/mixxx: upgrade to 2.4.2

https://github.com/mixxxdj/mixxx/blob/2.4.2/CHANGELOG.md

community/mixxx/APKBUILD

 # Maintainer: fossdd <fossdd@pwned.life>
 pkgname=mixxx
-pkgver=2.4.1
-pkgrel=2
+pkgver=2.4.2
+pkgrel=0
 pkgdesc="DJ mixing software"
 url="https://www.mixxx.org/"
 arch="all"
@@ -74,5 +74,5 @@ package() {
 }
 
 sha512sums="
-f62e0ce3bd016d411eda544a621e33b791517931c268391089cfe3101cd1e123eeb0b80bc8c138e7c67bb41cf378c6973f5c9284d5c720c693fd632f62372569  mixxx-2.4.1.tar.gz
+f6478012ba5fbfd4125838e78657d681ace7d9e4eb3f18534d550cd90ce2663952d7780675993d2cb2ff81683004f9cea19827dd2d6ead87b5029326689e6b3a  mixxx-2.4.2.tar.gz
 "