Update z.lua zsh plugin to allow customization of the fzf command used for fuzzy finding.

- Introduced new environment variable _ZL_ZSH_FZF to specify the fzf command
- Updated the eval statement to use the custom fzf command if provided by the user

Author: skywind3000

z.lua.plugin.zsh

@@ -21,7 +21,9 @@ fi
 
 export _ZL_FZF_FLAG=${_ZL_FZF_FLAG:-"-e"}
 
-eval "$($ZLUA_EXEC $ZLUA_SCRIPT --init zsh once enhanced fzf)"
+_ZL_ZSH_FZF=${_ZL_ZSH_FZF:-fzf}
+
+eval "$($ZLUA_EXEC $ZLUA_SCRIPT --init zsh once enhanced $_ZL_ZSH_FZF)"
 
 if [[ -z "$_ZL_NO_ALIASES" ]]; then
   alias zz='z -i'