Remove unnecessary function

scripts/Common/OS/setup.fish

@@ -79,16 +79,6 @@ function runSetup
         end | runChroot "$mountDir" tee /root/.bash_profile >/dev/null
     end
 
-    function prepareNix -V dir
-        source "$dir/../../lib/nix.fish"
-        source "$dir/../../lib/settings.fish"
-        set -l mountDir (getOSConfig partition.rootDir)
-
-        # Copy `nixpkgs` channel
-        mkdir -p (dirname "$mountDir/$nixPkgsDir")
-        cp -r "$nixPkgsDir" "$mountDir/$nixPkgsDir"
-    end
-
     function actionPreRun
         echo "Partitioning drives..."
         and getOSConfig partition.script >"$script"