ci-images: install diffutils prior to building images

Ensure the podman image used for generating Samba CI images includes
'diff' utility

Signed-off-by: Uri Simchoni <uri@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Thu Jun  9 23:48:42 UTC 2022 on sn-devel-184

.gitlab-ci-main.yml

@@ -42,7 +42,7 @@ variables:
   # Set this to the contents of bootstrap/sha1sum.txt
   # which is generated by bootstrap/template.py --render
   #
-  SAMBA_CI_CONTAINER_TAG: a9f12c7712cfccf1bf957d6976dc87917524b55e
+  SAMBA_CI_CONTAINER_TAG: 34eff4df0b3dbbfabcd74d5c50c357a6faa280d5
   #
   # We use the ubuntu1804 image as default as
   # it matches what we have on sn-devel-184.

bootstrap/.gitlab-ci.yml

@@ -13,6 +13,8 @@
     SAMBA_CI_IS_BROKEN_IMAGE: "no"
     SAMBA_CI_TEST_JOB: "samba-o3"
   before_script:
+    # install prerequisites
+    - dnf install -qy diffutils
     # Ensure we are generating correct the container
     - uname -a
     - cat /etc/os-release

bootstrap/sha1sum.txt

@@ -1 +1 @@
-a9f12c7712cfccf1bf957d6976dc87917524b55e
+34eff4df0b3dbbfabcd74d5c50c357a6faa280d5