build: bump alpine release

Required for Go 1.20

build.sh

@@ -22,7 +22,7 @@ buildah config --entrypoint='["/entrypoint.sh"]' --cmd='["/usr/sbin/openvpn", "/
 buildah commit "${container}" "${repobase}/nethsecurity-vpn"
 images+=("${repobase}/nethsecurity-vpn")
 
-container_api=$(buildah from docker.io/alpine:3.16)
+container_api=$(buildah from docker.io/alpine:3.20)
 buildah run ${container_api} apk add --no-cache go easy-rsa openssh sqlite
 buildah run ${container_api} mkdir /nethsecurity-api
 buildah add "${container_api}" api/ /nethsecurity-api/