Workaround missing DIB on stable jobs

This should fix Train and Stein jobs failing due to missing DIB.
Probably we can remove this once fixes on Octavia side [1][2] are
merged and ported to Train.

[1] https://review.opendev.org/#/c/736965/
[2] https://review.opendev.org/#/c/736824/

Change-Id: I8f5a141704c0a7c2095134c4afce2433e83f9415

.zuul.yaml

@@ -33,6 +33,9 @@
     name: kuryr-kubernetes-tempest-train
     parent: kuryr-kubernetes-tempest
     override-checkout: stable/train
+    required-projects:
+    - name: openstack/diskimage-builder
+      override-checkout: 2.30.0
     vars:
       devstack_localrc:
         USE_PYTHON3: True
@@ -41,6 +44,9 @@
     name: kuryr-kubernetes-tempest-stein
     parent: kuryr-kubernetes-tempest
     override-checkout: stable/stein
+    required-projects:
+    - name: openstack/diskimage-builder
+      override-checkout: 2.30.0
     vars:
       devstack_localrc:
         USE_PYTHON3: True