When the kickstart is handed off to Anaconda for building it will
download its own copy of the metadata and re-run the depsolve. So if the
dnf cache isn't current there will be a mismatch and the build will
fail to find some of the versions in final-kickstart.ks
This adds a new context to DNFLock, .lock_check, that will force a check
of the metadata. It also implements its own timeout and forces a
refresh of the metadata when that expires because the dnf expiration
doesn't always work as expected.
Resolves: rhbz#1631561