For centos stream, the $releasever is just the major version. Several
of our .repo files are using $releasever in their path, and I think
that 8-stream installs are actually using 8 repos to install from.
For 9-stream, which doesn't have a corresponding 9, we're getting
errors enabling some of the aarch64 tests.
Replace all the $releasever expansions in the .repo files with the
exact version they are being installed for. They don't need to be
generic; we are installing these specific repos for each DIB_RELEASE,
so they don't mix-and-match.
Change-Id: I48d438d8f51280cd060433fc8a67358d8345287f
