Move automatic updates by default from tier-0 to tier-1

tier-1 is more opinionated and automatic updates by default is
definitely a very strong opinion.

This makes it easier to inherit from tier-0 without having to undo that
knob if it's not desirable.

Prep for !48.

tier-0/autoupdates.yaml

@@ -1,9 +0,0 @@
-# Enable automatic updates by default
-postprocess:
-  - |
-    #!/usr/bin/env bash
-    set -euo pipefail
-    target=/usr/lib/systemd/system/default.target.wants
-    mkdir -p $target
-    set -x
-    ln -s ../bootc-fetch-apply-updates.timer $target

tier-0/manifest.yaml

@@ -50,7 +50,6 @@ include:
   - bootupd.yaml
   - ostree.yaml
   - initramfs.yaml
-  - autoupdates.yaml
   - basic-fixes.yaml
 
 packages: