Typo fix for update

Author: alecbcs

outputs/basics.sh

@@ -22,7 +22,7 @@ spack config add "config:suppress_gpg_warnings:true"
 example basics/source-setup     ". share/spack/setup-env.sh"
 
 # pin repository to release
-example basics/repo            "spack repo update --tag $packages_release"
+example basics/repo            "spack repo update builtin --tag $packages_release"
 
 # spack list
 example basics/list            "spack list"