feat: only run gpg ssh init on systems where it is present

runcoms/zshrc

@@ -11,9 +11,11 @@ if [[ -s "${ZDOTDIR:-$HOME}/.zprezto/init.zsh" ]]; then
 fi
 
 # Customize to your needs...
+if type gpg-connect-agent > /dev/null; then
   export GPG_TTY="$(tty)"
   export SSH_AUTH_SOCK="/run/user/$UID/gnupg/S.gpg-agent.ssh"
   gpg-connect-agent updatestartuptty /bye > /dev/null
+fi
 
 function mkcd() { mkdir $1 && cd $1 };