Add workarounds for ffmpeg/kf5/oneVPL mess

So...there's an ffmpeg update:
https://bodhi.fedoraproject.org/updates/FEDORA-2023-a5e10b188a
which went stable. It includes new sonames of all the ffmpeg
libs. It also pulls in a thing called oneVPL, which has a bug
that breaks ostree composes.

There's a big kf5 update:
https://bodhi.fedoraproject.org/updates/FEDORA-2023-b086a98f78
which contains kf5-kfilemetadata, which is built against ffmpeg.
Neal made sure that update's build of it was built against the
new ffmpeg and submitted both for stable at once - but the tests
on the kf5 update failed because they weren't run against the
new ffmpeg as it wasn't yet stable, and the kf5 update was
ejected from the push because of the failed tests.

So now we have the ffmpeg update stable but not the
kf5-kfilemetadata rebuild for it, which will break KDE stuff,
and the oneVPL issue means ostree composes will all fail.

This adds the ffmpeg update as a workaround so we can re-run the
tests for the kf5 update and get them to pass so we can push it
stable. It also adds the oneVPL update as a workaround so ostree
compose tests don't start failing.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

lib/utils.pm

@@ -479,7 +479,7 @@ sub setup_workaround_repo {
     my %workarounds = (
         "36" => [],
         "37" => [],
-        "38" => [],
+        "38" => ["FEDORA-2023-a5e10b188a", "FEDORA-2023-a433b7cf46"],
         "39" => [],
     );
     # then we'll download each update for our release: