Revert "Bootable Containers: Enable composefs by default"

See: https://gitlab.com/fedora/ostree/sig/-/issues/35

This reverts commit 20d8158735.

common.yaml

@@ -32,7 +32,6 @@ conditional-include:
   # Manifests included only for the Bootable Container variants
   - if: bootable_container == true
     include:
-      - composefs.yaml
       - bootc.yaml
       - dnf5.yaml
 

composefs.yaml

@@ -1,11 +0,0 @@
-# Set up composefs by default
-# See: https://fedoraproject.org/wiki/Changes/ComposefsAtomicCoreOSIoT
-postprocess:
-  - |
-    #!/usr/bin/env bash
-    set -xeuo pipefail
-
-    cat >> /usr/lib/ostree/prepare-root.conf << 'EOF'
-    [composefs]
-    enabled = yes
-    EOF