Remove APT upgrade on restore.

This could affect performance and make the action moot. Will add better version reporting so the user knows what cache they are locking into.

restore_pkgs.sh

@@ -22,9 +22,6 @@ for package in $packages; do
   cache_filepath=$cache_dir/$package.tar.gz
   echo "* Restoring package $package ($cache_filepath) from cache... "
   sudo tar -xf $cache_filepath -C $cache_restore_root
-  # Upgrade the install from last state.
-  # TODO(awalsh128) Add versioning to cache key creation.
-  sudo apt-get --yes --only-upgrade install $package
 done
 
 echo "Action complete. $cache_filename_count package(s) restored."