common.yaml: re-enable composefs on el9

The composefs issue (https://issues.redhat.com/browse/RHEL-63985) should
now be fixed in the latest el9 kernel. So let's optimistically re-enable
it. Now that we have tests for now, CI will validate this for us as
well.

kola-denylist.yaml

@@ -45,15 +45,6 @@
   osversion:
     - rhel-9.4
 
-# There are issues currently on ppc64le and kernel-64k in el9 that break
-# with composefs.
-- pattern: ext.config.shared.composefs.enabled
-  tracker: https://issues.redhat.com/browse/RHEL-70199
-  osversion:
-    - c9s
-    - rhel-9.6
-    - rhel-9.4
-
 - pattern: ostree.sync
   tracker: https://github.com/openshift/os/issues/1720
   snooze: 2025-02-11

manifest-el9-shared.yaml

@@ -16,5 +16,5 @@ postprocess:
     # https://issues.redhat.com/browse/RHEL-63985
     if [ -f /usr/lib/ostree/prepare-root.conf ]; then
       grep -q 'enabled = true' /usr/lib/ostree/prepare-root.conf
-      sed -i -e 's,enabled = true,enabled = no,' /usr/lib/ostree/prepare-root.conf
+      sed -i -e 's,enabled = true,enabled = maybe,' /usr/lib/ostree/prepare-root.conf
     fi