testing/xmrig: upgrade to 6.15.3

Ref https://github.com/xmrig/xmrig/releases/tag/v6.15.3

testing/xmrig/APKBUILD

 # Contributor: Oleg Titov <oleg.titov@gmail.com>
 # Maintainer: Oleg Titov <oleg.titov@gmail.com>
 pkgname=xmrig
-pkgver=6.15.2
+pkgver=6.15.3
 pkgrel=0
 pkgdesc="XMRig is a high performance Monero (XMR) miner"
 url="https://xmrig.com/"
@@ -33,6 +33,6 @@ package() {
 }
 
 sha512sums="
-17e8f5bbbd1ce1bd834db0a9d1cae2635390a62ae370c9ab2fada1cde2d49dffde12da7b4c7ab0d61e9b9776067c760b9bb936ac8440c6b825de3e5850559a9c  xmrig-6.15.2.tar.gz
+8c20e2a89405cb7fb3763b6184f6db9dbbdb6628e6d5d3cb62c35d87aa4c54daab5efe8682ed0f0ec3bb6577af0d0e5f41f2f864d52eee41081449e372649a2a  xmrig-6.15.3.tar.gz
 40cd7e3a884920951ec48efebbea5d7181deaeef6a226444a46ad8dc83b54eceae954c8d28952c21d63a15a4947eac72d1024b83684b5cb15437d3c8d32b006a  enable-donateless-mode.patch
 "