tier-1: drop a bunch of redundant packages

These are all included in tier-x or tier-0 already.

Though it does drop bsdtar. This isn't really well-known enough to
belong here. It's included in FCOS because we use it in our scripts,
but it's not a requirement for any tier-1 logic AFAIK and I would be
surprised if users expected it there.

tier-x/manifest.yaml

@@ -38,4 +38,5 @@ packages:
   # rpm-ostree
   - rpm-ostree nss-altfiles
   # firmware updates
+  # If you're using linux-firmware, you probably also want fwupd
   - fwupd