Fix all variants to delete-after so we dont keep accumulating things.
In 57985b0 nightly was updated, but not all the variants were updated
in the second sync. The first sync runs with --exclude repodata, then
the second one includes that and also does a --delete-after, but we only
updated the first one. This should clean up old artifacts.
Signed-off-by: Kevin Fenzi <kevin@scrye.com>