Fix upgrade function, add yubikey notification for ssh.

config/zsh/aliases.zsh

@@ -48,3 +48,10 @@ function ud() {
   for i in ${LOCAL_GIT_DIR}/dotfiles ${LOCAL_GIT_DIR}/zsh_modules/*; do git -C ${i} pull; done
   nvim -c "lua require('lazy').sync({wait = true})"
 }
+
+function upgrade() {
+  case $(lsb_release -si) in
+    Gentoo) eix-sync && eix-update && emerge -avuNDU @world ;;
+    VoidLinux) xbps-install -Su && xbps-remove -RoO && xlocate -S ;;
+  esac
+}