Make steeef theme much faster by not iterating through all history (#6359)

* Make steef much faster by not printing all history each time

* Use whence -c to expand shell functions as well

* Use $2 (expanded command about to be ran)

themes/steeef.zsh-theme

@@ -62,7 +62,7 @@ zstyle ':vcs_info:*:prompt:*' nvcsformats   ""
 
 
 function steeef_preexec {
-    case "$(history $HISTCMD)" in
+    case "$2" in
         *git*)
             PR_GIT_UPDATE=1
             ;;