Remove lower-constraints job

As discussed during the upstream ironic community meeting on
Monday Dec 14 2020, the lower-constraints job is being removed.

Also Cap version of ipa-builder to 2.2.0

Versions higher than 2.2.0 of ironic-python-agent-builder use
tinycore 11.x to build tinyipa, and that uses a kernel too recent
to be built on bionic.

Change-Id: Ide0f6c38a59ae6486fa33cfb19b383d022e57d5a
(cherry picked from commit 78b356cd44)
(cherry picked from commit 95e1cd54cb)

zuul.d/ironic-python-agent-jobs.yaml

@@ -12,6 +12,8 @@
       - ^tox.ini$
     required-projects:
       - openstack/ironic-lib
+      - name: openstack/ironic-python-agent-builder
+        override-checkout: 2.2.0
     vars:
       devstack_localrc:
         IRONIC_RAMDISK_TYPE: tinyipa
@@ -147,6 +149,9 @@
     name: ironic-standalone-ipa-src
     parent: ironic-standalone
     description: Test ironic standalone with IPA from source
+    required-projects:
+      - name: openstack/ironic-python-agent-builder
+        override-checkout: 2.2.0
     vars:
       devstack_localrc:
         IRONIC_DEFAULT_BOOT_OPTION: netboot
@@ -160,7 +165,8 @@
     parent: metalsmith-integration-glance-localboot-centos7
     required-projects:
       - openstack/ironic-python-agent
-      - openstack/ironic-python-agent-builder
+      - name: openstack/ironic-python-agent-builder
+        override-checkout: 2.2.0
       - openstack/ironic-lib
     vars:
       devstack_localrc:
@@ -173,6 +179,8 @@
     parent: ironic-ipa-base
     required-projects:
       - openstack/diskimage-builder
+      - name: openstack/ironic-python-agent-builder
+        override-checkout: 2.2.0
     timeout: 9600
     vars:
       tempest_test_timeout: 2400

zuul.d/project.yaml

@@ -1,7 +1,6 @@
 - project:
     templates:
       - openstack-python3-ussuri-jobs
-      - openstack-lower-constraints-jobs
       - openstack-cover-jobs
       - publish-openstack-docs-pti
       - check-requirements