remove reference to repo pinning

Author: kshea21

outputs/basics.sh

@@ -21,9 +21,6 @@ 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 builtin --tag $packages_release"
-
 # spack list
 example basics/list            "spack list"
 example basics/list-py         "spack list 'py-*'"