[CI] Move to Debian Bullseye

Wallaby upgrades run on Buster.
To be amended in Xena.

Change-Id: I8d3a320c9fb19e18d959c555d16b736b85e010cd

zuul.d/jobs.yaml

@@ -11,7 +11,7 @@
 - job:
     name: kolla-ansible-debian-source-aarch64
     parent: kolla-ansible-debian-source
-    nodeset: kolla-ansible-debian-aarch64
+    nodeset: kolla-ansible-debian-bullseye-aarch64
     voting: false
     timeout: 10800
     required-projects:
@@ -20,7 +20,7 @@
 - job:
     name: kolla-ansible-debian-source
     parent: kolla-ansible-base
-    nodeset: kolla-ansible-debian
+    nodeset: kolla-ansible-debian-bullseye
     voting: false
     vars:
       base_distro: debian
@@ -134,7 +134,7 @@
 - job:
     name: kolla-ansible-debian-source-upgrade
     parent: kolla-ansible-base
-    nodeset: kolla-ansible-debian
+    nodeset: kolla-ansible-debian-buster
     timeout: 9000
     voting: false
     vars:
@@ -146,7 +146,7 @@
 - job:
     name: kolla-ansible-debian-source-upgrade-aarch64
     parent: kolla-ansible-debian-source-upgrade
-    nodeset: kolla-ansible-debian-aarch64
+    nodeset: kolla-ansible-debian-buster-aarch64
 
 - job:
     name: kolla-ansible-ubuntu-source-upgrade

zuul.d/nodesets.yaml

@@ -12,17 +12,29 @@
         label: centos-8-stream
 
 - nodeset:
-    name: kolla-ansible-debian
+    name: kolla-ansible-debian-buster
     nodes:
       - name: primary
         label: debian-buster
 
 - nodeset:
-    name: kolla-ansible-debian-aarch64
+    name: kolla-ansible-debian-buster-aarch64
     nodes:
       - name: primary
         label: debian-buster-arm64
 
+- nodeset:
+    name: kolla-ansible-debian-bullseye
+    nodes:
+      - name: primary
+        label: debian-bullseye
+
+- nodeset:
+    name: kolla-ansible-debian-bullseye-aarch64
+    nodes:
+      - name: primary
+        label: debian-bullseye-arm64
+
 - nodeset:
     name: kolla-ansible-focal
     nodes: