add git-prune alias

programs/zsh.nix

@@ -12,6 +12,9 @@
     };
 
     initContent = ''
+
+      alias git-prune="git fetch -p && git branch -vv | grep ': gone]' | grep -v '*' | awk '{print \$1}' | xargs -r git branch -D"
+ 
       # Use kitty's ssh helper if running inside kitty
       [ "$TERM" = "xterm-kitty" ] && alias ssh="kitty +kitten ssh"