Add debian-bullseye-arm64 build test

This does a basic vm build test of bullseye-arm64, which currently is
missing from the ARM64 testing.

To keep runtimes a bit more reasonable, split the job into two parts,
one for deb distros and one for rpm.

Change-Id: I0f28ff92e1b8d08d56b82b392e2cc355d567d007

.zuul.d/jobs.yaml

@@ -30,16 +30,28 @@
         - ubuntu/bionic-build-succeeds
         - ubuntu/focal-build-succeeds
 
+# NOTE(ianw) : these jobs are split to keep the build times a bit more
+# reasonable.
 - job:
-    name: dib-functests-arm64
+    name: dib-functests-arm64-deb
     description: |
-      ARM64 build tests
+      ARM64 build tests (Debian-like distros)
     nodeset: debian-bullseye-arm64
     parent: dib-functests-base
     vars:
       dib_functests:
         - ubuntu-minimal/bionic-arm64-build-succeeds
         - ubuntu-minimal/focal-arm64-build-succeeds
+        - debian-minimal/bullseye-arm64-build-succeeds
+
+- job:
+    name: dib-functests-arm64-rpm
+    description: |
+      ARM64 build tests (RPM-like distros)
+    nodeset: debian-bullseye-arm64
+    parent: dib-functests-base
+    vars:
+      dib_functests:
         - centos-minimal/8-aarch64-build-succeeds
         - centos-minimal/8-stream-aarch64-build-succeeds
         - openeuler-minimal/20.03-LTS-SP2-build-succeeds

.zuul.d/project.yaml

@@ -38,7 +38,8 @@
             voting: false
     check-arm64:
       jobs:
-        - dib-functests-arm64
+        - dib-functests-arm64-deb
+        - dib-functests-arm64-rpm
     gate:
       jobs:
         - openstack-tox-pylint

diskimage_builder/elements/debian-minimal/test-elements/bullseye-arm64-build-succeeds/README.rst

@@ -0,0 +1 @@
+Verify we can build a debian-minimal stable image.

diskimage_builder/elements/debian-minimal/test-elements/bullseye-arm64-build-succeeds/element-deps

@@ -0,0 +1,2 @@
+block-device-efi
+vm

diskimage_builder/elements/debian-minimal/test-elements/bullseye-arm64-build-succeeds/environment.d/10-set-distro.bash

@@ -0,0 +1 @@
+export DIB_RELEASE=bullseye