Drop gnupg dependency in build scripts

packaging/resources/apkbuild-source-stable-optimized.sh

@@ -12,7 +12,7 @@ pkgdesc='A simple, self-hosted, SSH-synchronized password/note manager for the C
 arch='all'
 url='https://github.com/rwinkhart/MUTN'
 license='MIT'
-depends='gnupg'
+depends=''
 makedepends='busybox go'
 options='!check net'
 source=\"\$pkgname-\$pkgver.tar.gz::"$source"\"