Disable job for blank image ...

It does not make sense to keep running it.

Signed-off-by: Harald Jensås <hjensas@redhat.com>

Author: hjensas

zuul.d/projects.yaml

@@ -6,8 +6,8 @@
         - hotstack-pre-commit
         - devsetup-hotstack-os
         - vexxhost-hotstack-ipxe-image
-        - vexxhost-hotstack-blank-image
         - vexxhost-hotstack-controller-image
+        # - vexxhost-hotstack-blank-image
     github-experimental-trigger:
       jobs:
         - vexxhost-hotstack-sno-2-bm